She could die because of the pregnancy DF, we all could!
But isn't it about weighing up the possible risks ( which increase with age ) and considering what is best not only for you, but any other children you have?
I know that if there was a considerably higher risk of me dying having another baby, then i wouldn't have one because my son, that is already here and alive deserves for me to be around as long as possible.
Her descision ( if she can find a 'doctor' to help her ) is entirely selfish and most probably potentially will damage her daughters life and the baby she might carry, not just her own.
Thats why somethings should just not be allowed.