It seems a bit paranoid to me.
Paranoia or caution?
If you watched your mother die at a young age from a horrible disease, and you knew that you carried the genes for that disease, you would not think it paranoid to remove organs that you are no longer going to use. The risk from surgical complications is insignificant compared to the near certainty of getting ovarian cancer.
I think she carries a gene that yields a 85% chance of cancer.