Washington (CNN) -

As Ann Romney begins to take center stage at next week's Republican convention, we are learning more about some of the problems she has endured and how she fought back.

The Romneys, who are protective of the details of their private family life, have spoken often about Ann's battle with multiple sclerosis which was diagnosed in 1998. After the Super Tuesday primaries, she had a recurrence which she kept secret at the time but has since discussed in an interview with CNN.

Mrs. Romney also has described to CNN how she successfully fought an early-stage breast cancer diagnosis in 2008.

Several months after the couple's youngest son, Craig, was born in 1981, Ann had emergency surgery. After not feeling well, she was rushed to the hospital where doctors found a growth in her abdomen, two sources familiar with the situation told CNN.

Around 1991, ten years after Craig's birth, the couple suffered a miscarriage, the sources confirmed. Ann was about four and a half months pregnant when it happened. The sources refused to speak on the record because the Romneys did not want the details made public.

The Associated Press first reported on Saturday Mrs. Romney had had a stillbirth, but sources told CNN it was in fact a miscarriage.

Those close to the Romneys say Ann's medical problems and how she recovered from them exemplify her strength of will and determination.