“Her” (take a look at a picture) age is a bit obscure, but according to the “People” link Petitfour mentioned, she was 50 when the baby was born.
It’s perfectly reasonable for a healthy woman to have a baby when she’s 50. The rest of the situation is what’s crazy here.
If she hasn't experienced menopause it is.
Must have been a donor egg. By 50 chance in downs syndrome and other genetic problems get to be 1 in 10 or worse. Chance of miscarriage goes to 50%.
Don’t know if she has other kids, but to have your first kid at 50 is pretty much impossible without a lot of intervention.