Battling breast cancer at age 37, Australian pop star Kylie Minogue is planning her future in fast-forward. Though no engagement has been announced, she and her French actor beau Olivier Martinez "want to be together forever, and they definitely want children," says a source close to the couple, who are staying in Martinez's Paris home. "Becoming a mother is Kylie's priority now," says the source. But chemotherapy, which she needs to treat the cancer, can destroy a woman's fertility, so the singer is trying an experimental surgery in which doctors remove slivers of ovarian tissue to be frozen and reimplanted when the patient is cancer-free. "This could help thousands of women whose ovaries have been destroyed by cancer treatment to become mothers," says Belgian doctor Jacques Donnez, who led the research in the procedure, which has been performed only about a dozen times. Last year a Belgian cancer survivor became the first to give birth after having the ovarian transplant. "That story moved Kylie greatly," says the friend. "She would love to do the same."

For now she is connecting with kids in other ways: aiding orphans of the December tsunami and visiting a children's cancer ward in Melbourne. "It was just as much for Kylie as it was for the kids," says David Rogers, who organized the July 7 visit through his charity. "It boosted her spirits." Since then Minogue, who has had four cancer surgeries, has been lying low. At her side is a doting Martinez, 39, who before her May diagnosis gave Minogue a $60,000 ring as "a symbol of their love," says a source. As sister Dannii Minogue told PEOPLE, "I wish everyone who was sick had someone like him to look after them."