My 13 -year-old daughter spends all her time on her computer, and recently she's become very secretive as well. She's often texting and giggling and won't tell us what it's about. I became so worried, I'm afraid I got into her email when she was out – not difficult to guess her password, it was the name of our cat – and was horrified to find she's in touch with some bloke who has been sending her all these sexual messages. He says he's 15, but I'm pretty sure it's some older man, by the way he writes. What can I do? Yours sincerely, Susie

Virginia says... What you can do is thank your lucky stars that your daughter is still under age and that you still have some power over her. I would email this man at once and say who you are and say that if he ever contacts her again, you will get in touch with the police. Whether what he's doing is illegal doesn't matter. You don't say the exact nature of the messages. But the word "mother" and "police" will, I'm sure, be enough to make him drop out of your daughter's life for ever.

As for your daughter, you have to tell her what you've done. If she accuses you of doing something behind her back, and being treacherous, you can reply that her having a relationship with an unknown man on the internet was also secretive and treacherous. Ask her how she'd feel if she discovered you were spending your time whispering and tittering and chatting on the internet and then it turned out you were having some weird relationship with a guy you'd never met. How would she feel?

I don't know if honesty has been a quality that's featured large in your family life in the past, but from now on you must be completely open with her about everything you do and feel, and in return she must be honest with you. She doesn't have to show you her private emails, but she must tell you if she's having an internet liaison. You are her mother and she is only a child.

Whatever you do, don't be angry, but be compassionate. Explain how worried you are and put it to her that this so-called 15-year-old could actually not be 15 at all, but some creepy man – and here you must mention a man she finds particular repulsive, such as some hapless geography teacher – who is getting off on her replies and was anyway quite possibly softening her up for some very dangerous meeting.

If she agrees to be open and honest, you can say you'll let her keep her computer, but explain that you might occasionally ask if you can look at it if you ever get suspicious again. I would also talk to the parents of other children at the school and warn them of what's been going on, so that they can be on the alert as far as their own children's emails are concerned.

Once your daughter's older you won't have any hold over her. But however grown-up she seems, remember she is emotionally only a child. And, more importantly, legally. Don't feel ashamed of what you did. Remember that is actually your responsibility as a parent and an adult to protect her from potentially harmful behaviour like this.

Readers say...

Deal with it now

As a pastoral support assistant in a girls' secondary school, I have first-hand experience of this. Firstly, you need to tell her you know and get her to talk about it. Tell her it is not her fault, she is being used by a man who does not have her best interests at heart. Secondly, tell your daughter's school. They will be able to put some lessons or guidance in place for the whole school so your daughter won't know it is directed at her. Then you need to put some computer/phone restrictions in at home. You are doing the right thing, you are a good caring mother – but here tough love applies. Thirteen is too young to recognise all the dangers and this is a potentially very dangerous situation.

Frances, by email

Tell the police

In the name of all that's holy, this dilemma is not social or moral. It is potentially criminal. You must inform the local Police Child Protection Unit immediately. That's not next week, not tomorrow and not in five minutes. DO IT NOW. The description you give is classic adult grooming. It needs a police investigation.

Roger Cook, by email

Next week's dilemma

Dear Virginia, I'm a single parent and my son is 23. He's got a very poor degree from his university and is struggling to find a job. He has also recently been dropped by his girlfriend and is feeling very depressed – he lives in a house with some friends. My problem is that I have just discovered I have cervical cancer. No one can tell me what my chances are of survival. I have a supportive group of friends – but I just don't know whether to tell my son. I don't want to add to his worries. What should I do? Yours sincerely,Catrin>

What would you advise Catrin to do?

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