Brian Lynch caught sight of his wife, the US Open champion, breaking off from the packing yesterday and stand still, shaking her head for a moment. He told her what she had just done and Kim Clijsters said: “I did?” Yes, he replied.

“I said I had just had this thought about winning the Open and how crazy it all is,” she said. Crazy? Perhaps. Captivating? Most certainly.

It was time to go home time, to pack away Jada’s clothes, the steamer they had brought to prepare her food, all the knick-knacks, toys and frippery that 18-month-olds leave around. Oh yes and do not forget that shiny silver ornament in the corner that you picked up on Sunday when you won a grand-slam title in your third tournament back after retiring, gaining a husband, becoming a mum, losing a father, getting used to being that woman who used to be so good at tennis and then becoming so very much better at it.

The noise of the vacuum on the stairs of her hotel lobby jolted Clijsters back to the domesticity she will enjoy for the next couple of weeks while she tries to comprehend what she has accomplished. The clock has been rewound four years when she first won the US Open, there will be security at Brussels airport tomorrow when the family lands (Kim’s 90-day visa to the United States is about to expire), then it is off to her home town of Bree, where the locals will be treated to another slap-up lunch on her on Friday. They probably thought those days were gone.

Even as the ball looped gently from Caroline Wozniacki’s racket on Sunday night and fell into a space on the court where the Belgian could not miss, the improbability of it all was never far from Clijsters’s mind. When she took a telephone call from the All England Club in the spring asking if she would not mind being a part of their Centre Court roof unveiling, the thought of returning to mainstream tennis could not have been farther away.

“Really, I’d only hit the ball three or four times since my first career ended,” she said. “I had become pregnant, there was a further nine months of breastfeeding, I was helping take care of my father, who was so sick [Leo died of cancer in January never knowing his daughter would play professionally again], there was my husband to look after. To tell you the truth, having ten minutes to myself was a major relaxation.”

Armed with a cause — to get herself truly fit again — Clijsters took up the same programme she had when she played first time around, but with a greater intensity than before. “It was really a lot of physical work and then we kind of added tennis back on when I got closer to playing,” she said. “There was Jada to think of, of course. I didn’t want her to be so connected with me that I couldn’t leave her side, it’s important she is around a lot of family, she can sleep at her grandparents, she can sleep at my sister’s.

“At first, when I was leaving to go and train, I’d see her at the window crying and I’d have to rush back in and give her a big hug. I don’t know if that was the right thing to do. Now, I say to her, ‘Mummy’s going off to practise’ and she says, ‘Bye-bye’. Because she knows I’m coming home, everything is fine.

“It is nice to know that what I have done here might inspire a few people. Even before I started to play again, everyone was interested to know what stroller I was buying, what baby food Jada preferred, it is automatically a little different if you are a bit well known.”

More so now that Clijsters has become the first mother since Evonne Goolagong Cawley, from Australia, at Wimbledon in 1980 to win a grand-slam singles title. Cawley’s daughter, Kelly, was 3 at the time; Jada is a curly mopped energy bundle, as her scene-stealing performance at the presentation confirmed. Having Brian, her basketball-playing husband, here has also been an enormous advantage. “We were only dating in ’05 and he came to one match, I remember, but now he is such an influence on me,” Clijsters said. “He’s a real laid-back, quiet guy and that calms me down if I get nervous and a little overwhelmed, and, believe me, the right arm was tightening a bit in the final.”

There is a freshness about Clijsters that is magical to behold. She feels she never played a better match than her semi-final against Serena Williams, which ended in such a blaze of profanity, but she would have lost anyway because Clijsters did something she often failed to do against Williams — stay as strong in the mind as the sisters always have.

“I think I have an advantage,” Clijsters said. “In the past I couldn’t keep it going mentally, now I can.”

From entering the championship on a wild card, as a player without a ranking, Clijsters’s victory has enabled her to leap to No 19. Now comes some careful planning, where to play, how often, what disruptions she wants to have in her life. But mention Wimbledon and her eyes light up. “It’s a nice feeling to have that there is still a lot of margin for improvement and Wimbledon — who would not want to win that?” she said. “They wanted me to have a wild card this year but though it’s hard to say no, it did not feel right.”

And what of an inspirational effect might her return have on Justine Henin, who stepped away from the game on the brink of the 2008 French Open — a decision her compatriot still does not truly comprehend. If Kim, why not Justine? “I do think she’s planning something, if what I hear is right,” Clijsters said. “It seems she is practising hard and I really do believe she will come back.”

• Serena Williams was fined $10,000 (about £6,000) on Sunday for abusing the line judge during her semi-final defeat by Kim Clijsters. Yesterday she apologised. “I need to make it clear to all young people that I handled myself inappropriately and it’s not the way to act — win or lose, good call or bad call, in any sport, in any manner,” Williams, 27, said. “I like to lead by example. We all learn from experiences both good and bad, I will learn and grow from this.”

Mum's the word

• Kim Clijsters is the first woman to win a grand-slam singles title after giving birth since Evonne Goolagong Cawley won Wimbledon as a 29-year-old in 1980. The previous mother to win Wimbledon had been Dorothea Lambert Chambers, who was 35 when she won the last of her seven titles in 1914.

• In 1971, Margaret Court lost the Wimbledon final to Goolagong, her fellow Australian, while in the early stages of pregnancy. After giving birth to a son in early 1972, she won the other three grand-slam titles in 1973. She took her baby on tour with her, letting her husband mind the child as she played.

• Last year, Lindsay Davenport returned after a year off to have her first child. The former world No 1 won three of the first four tournaments she entered and rose to world No 21. She had a second child in June, but hopes to be back again soon.