It is only 15 months since she came out of retirement but Kim Clijsters' thoughts are already turning to the day when she will put away her rackets again – and this time there will be no turning back.
Having quit three years ago to start a family, the 27-year-old Belgian knows she will not want to lead a globe-trotting lifestyle when her daughter, Jada, who will be three in February, goes to school. Clijsters has never played at an Olympics – she was injured in 2004 and in retirement in 2008 – and may find the London Games of 2012, which will be staged at Wimbledon, an appropriate place to make her final bow.
Spending the last week at the end-of-season WTA Championships in Doha has underlined in Clijsters' mind where her priorities lie. This has been the first time that she has travelled to a tournament without her husband, Brian, a former basketball player, and Jada, whose parents thought it would be unfair to take her from the cold of a European autumn in Belgium into the desert heat and back again in a short space of time. Besides, the family will be back on the road in the new year for the Australian Open.
"I can see how important routine is for a child," Clijsters said. "Obviously I'm not going to go to Australia for a month and leave Jada and Brian in Belgium. I don't love playing tennis that much! That's not worth it for me. She doesn't have to go to school yet and for the moment we'll try to make it work as a family. Then we'll see. I'll try to keep it going until the Olympics, but if something happens in between where I really feel it's getting too much or too hard for her – or for me or my husband – it would be a very easy decision to make.
"My family is my priority in life. I enjoy playing tennis, but I've played for a good few years and I know I've given it everything that I have, so everything I gain now I see as a bonus. We do see it as a fun family thing that we can do together. My husband was never able to travel to tournaments with me in the first few months when we were together because he was still playing basketball and then I retired. He's enjoying that side of it, too."
The world No 4 found it hard to tear herself away from her family before leaving for Doha. "The night before I left I was sitting next to Jada's bed, explaining to her that I was going away, that Mummy would be going by herself and that Jada would be staying with Daddy," Clijsters said. "I was choking up, but Jada was fine. She just said: 'That's OK!' She was very easy about it. I said: 'We'll talk on the phone and I'll see you on the computer.' She just said: 'OK, Mummy. Can I go to the playground with Daddy?' She knows that this will be part of our lifestyle for a little bit longer, until I'm officially done and she starts going to school."
What has been the hardest part of being a mother and tennis player? "It's the guilty feelings that you have as a mother. I felt that a lot at the start, though now it's better. I was home for the first year with Jada every day, taking care of her and breast-feeding, so the connection there was very strong. When I started to get back into my tennis schedule, in the first couple of days she would start crying when I left the house and I would feel really guilty going to the tennis courts and leaving her. But the nanny said that within a couple of minutes of me leaving Jada was fine.
"Obviously sometimes those guilt feelings come back a bit, but I think every mother wants to be with their children more of the time when they're working. That's life and I think it's good for the children to socialise with other people and not just be with their family all the time."
Clijsters became the first mother for 29 years to lift a Grand Slam singles title when she won last year's US Open in only the third tournament of her comeback. She retained her title last month, though her first full year back was not without difficulty. An ankle injury interrupted her spring programme and Doha has been her first appearance since New York after she had two moles removed.
The latter part of the first stage of her career was dogged by injury, but Clijsters feels stronger now. Knowing her body better has been crucial. The heat and humidity have been gruelling in Doha, but Clijsters wisely took time to adjust to the conditions. "As much as I wanted to practise a lot and get used to playing outdoors again, I knew it wouldn't be the smartest thing to do, to push your body through these conditions when you're adjusting to the climate change," she said. "A younger player might not think like that and might think they need to practise more and more, but that's not always the best option. It's a fine line between practising enough and not pushing your body too much.
"I've never been a player who likes to practise for six hours a day. I prefer more intense, shorter sessions. I also need a lot of variety. I do swimming, mountain biking, canoeing, boxing, yoga. I need that variety to keep it fun and to keep me interested."
Clijsters said being away from her family had not necessarily helped her tennis. "It's not like the family are a distraction from my tennis when they're with me. I just have to balance it differently. Even when I'm in Belgium Jada still sleeps in the afternoon, so I try to do an early practice, then I'm home. When she goes to sleep, I go for another workout or to the gym. The planning hasn't had to be as precise here. It's a little bit easier in that way – but of course I would still have liked to have had them here with me."
Kim Clijsters looked a little shaken after being involved in a "scary" car crash on her way to the WTA Championships semi-finals in Doha yesterday but there was no stopping her once she had won the first set against Sam Stosur.
The US Open champion beat her Australian opponent 7-6 6-1 to reach the final of the season-ending tournament in the Qatari capital. She will now face either Caroline Wozniacki or Vera Zvonareva, the world No 1 and No 2 respectively, in the $4.5m (£2.8m) showpiece.
"Samantha and I have had some really tough matches against one other throughout our whole careers so I knew that I had to be ready to come out here and try and play my best," said Clijsters. "I played well at the important points and I think that's why I won the first set, and then in the second set I felt maybe she dropped her game a little bit.
"I had an early chance to break, and I did, and that gave me a little bit more confidence to just try to serve it out every time."
Clijsters, who told her Twitter followers that she had been "very lucky" to escape from the crash unhurt, lost the opening three games of the match and had to fight off a set point before taking the first set in a tie-break.
Stosur, who reached a career-high ranking of fifth in the world earlier this year and was runner-up in the French Open, was unable to capitalise on the promising start as Clijsters produced some of her best tennis of the tournament to take a rapid 3-0 lead in the second set.
The Belgian then broke Stosur again to take a 5-1 lead with a backhand down the line and proceeded to wrapped up the second set in 26 minutes, reaching her first WTA Championship final for seven years.