For half the year, Sharon Truelove is a stay-at-home mother. But the rest of the time, she's an aid worker in desperate situations around the globe. She describes how her family copes with the change

For every working mother, that moment when you open the front door at the end of a long, hard day, and see your children hurtling down the hallway towards you makes your heart skip. But for me it's extra special because by the time I reach my front door it is often more than a month since I saw them.

For almost three years, I've been on call as a British Red Cross aid worker. The phone rings and – sometimes within 48 hours – I'm on a flight to wherever my skills are needed most. For up to six months of every year, I'm on the other side of the world, working in desperate situations. Meanwhile, home alone in the Cotswolds, my husband Julian copes heroically with a sudden switch to life as a single dad to Rowan, 11, Finnian, seven, and Orla, six.

Although I try never to be away for longer than five weeks, that is still a painfully long time to be separated from them all, and I know it's very hard on them too. Julian does a fantastic job on his own with them – while holding down a job as a computer scientist – but five weeks is as long as any of us can manage, practically and emotionally.

Knowing that I will soon be boarding a plane to Haiti for the third time since the earthquake struck, my youngest clings to me constantly and wants to spend every night in my bed. And when it is time to go, there will be tears – not all hers.

Leaving gets a little easier each time I go, as we all grow in confidence that we will survive it, and we will be together, under one roof again before too long. But I don't pretend that it's easy for any of them – perhaps least of all for a little girl of six – to see their mum disappear to somewhere they've only ever seen on the news. Somewhere dangerous, where people are dying.

At the most recent school parents' evening, her teacher took me to one side and said that Orla had been very withdrawn during my last stint in Haiti. I thought I felt as guilty as it was possible to feel about it, but at that moment my heart sank to a new low.

I do feel guilty about leaving them, about not being there and not talking to them every day. So why do I do it to them, to my poor husband, and myself? The answer is because I have no doubt – on all but the most exhausting days in the field – that the benefits to us all far outweigh the downsides.

After my family, aid work is what I am most passionate about. I have a degree in development studies and a Masters in irrigation, and soon as I graduated I have worked abroad. But then, later in my twenties, I met Julian and realised that I wanted to have a family, I decided I'd better switch from aid work to teaching, to make it possible. I taught for a short while but my heart was never in it. When Rowan, our eldest was about one, I got a job with the British government in Botswana, so we moved there as a family for a year.

With just one, very small, child, it was possible to live that life. But as our second and third children came along, I felt as though I had to accept that aid work and motherhood simply don't mix. I was unemployed for a number of years and although I loved being a mum, I felt that having lost my work I'd lost a really big part of who I was.

Even if you're keen to return to the field, as a woman with children it's very hard to find agencies willing to take you on. The job requires the kind of flexibility and commitment a lot of men and women with families would struggle to meet. But Julian saw how important it was for me to get back to doing what I do. I was qualified to do it and, until I became a mother I had relished the challenges that every assignment threw at me.

He saw the effect that not being able to do it was having on me. It changed me. My confidence was sapped and I felt so frustrated. Thankfully, he didn't want having had kids to cut me off from such an important part of my life. We didn't want to set that example to the kids. He wanted to find a way to make it work, and without his support it just wouldn't have been possible.

So in 2007, after five years away, the British Red Cross took a chance on me. My first assignment was in the Maldives, working on the Tsunami relief programme, and we went there as a family of five. It sounds like heaven, living on a beach in a tropical paradise, but to take the family was quite a risk. Although I loved being back at work, my husband hated it there. He was bored stiff after about a month because there was so little for him and the kids to do. Culturally, it was a great experience for them to live somewhere so different. It made them worldlier than their friends and unafraid of adventure.

There was no schooling for Orla and Finnian. But Rowan, who was eight, went to a local school which left him with a lot of catching up to do when we got home. He is still catching up now, which has been pretty tough on him. But in the time I have spent at home we have worked really hard to get him up to speed.

The impact of that year in the Maldives on his education really brought home the impracticalities of travelling with my family. A lot of aid workers do take their kids with them on longer deployments, even to fairly challenging places. But for a large family with school-age children, I don't feel it's sensible or fair on them. The alternative for many overseas workers is to send their children to boarding school, but Julian and I didn't want that for ours. The only option seemed to be for me to try it alone.

To prove to myself that I could do it, I got a three-month placement in with Voluntary Service Overseas working for the department of Agriculture in Ghana. It was an incredibly painful time: heart-breaking homesickness fed into a lack of confidence in my ability to do the job. No trip I've taken before or since has ever hit me so hard emotionally, and that's when I knew that if I was going to do this, I'd have to stick to short trips, especially while the children are so little.

But even now, on those days on the job when I am exhausted, ill, stressed, sleep-deprived, it is sometimes just too difficult to think about home, Julian and the kids. I can't look at their photographs and I can't speak to them on the phone, because I don't feel strong enough not to cry.

Even though working in places like Haiti – which still, nine months on, is one of the most challenging environments I have ever worked in – is about as far from a holiday as you can get, it refreshes me for life as a parent when I get home. Just as being a stay-at-home mum refreshes me for the next trip abroad.

When I'm with my kids, I'm with them 100 per cent. Unlike the other mums doing the daily nine to five, I get a break from the daily grind of parenthood. I'm not too tired to enjoy the time I spend with them. We try to do the things we enjoy together – like cycling down to the farm shop for an ice-cream, or inviting friends over for tea – as much as we can when I'm home. I even quite enjoy the school run and the daily battle to get homework done each night. Picking up socks is less of a joy, but it doesn't get me down because I appreciate everything about being a mum more because I don't do it all the time.

Until I next set off for Haiti for the third time since the earthquake struck, I'll be a tidying, batch-cooking, gardening machine. I'm on my usual mission to fill the freezer with easy meals, to empty every laundry basket, and get the garden back in some sort of order before I set off again. Because when Julian is on his own with them, doing the basics is all he has time for. Keeping three children fed, watered and happy is a harsh routine, so I do whatever I can to make it easier for him.

I was on my way home from my second trip to Haiti, with my heart set on seeing my family again, when the Chilean earthquake struck. I knew that as a Spanish speaker, there would be a mass of messages on my phone and email by the time I landed in the UK, asking if I could get out there. When you know the agencies have such a small pool of qualified people to choose from, it can be hard to turn those requests down. But I know the people I help when I'm working don't need me, they just need someone who can do the job. But there is only one person who can be a mother to my children and a wife to my husband.

The bottom line is, my family's needs really do come first. But with their support, I have the best of both worlds and I hope that when I open the front door they feel that they do too.


Dealing with a parent's absence

* The website advises explaining in an age-appropriate way that the parent is going away, to help the child prepare for this. Ensure parents remain positive so children do not pick up on tense emotions.

* Show the child where the parent is going on a map, atlas or Google Earth. Buy a calendar for the child and mark the special dates.

* The parent who is going away could record bedtime stories on a CD to play to the child.

* Although emails and phone calls are great, postcards and gifts are touching for the child.

* Wherever possible, use a webcam when communicating. During the separation, keep the routine as normal.