Fi, that's terrible for everyone involved. It's very sad.

I have a close friend with a sister who is intellectually impaired. She can look after herself with help but it was still a concern for them what would happen if she became pregnant as she is now living in shared housing. Recently, the family arranged for her to have a tubal ligation. It wasn't an easy decision for them but I can fully understand why they did it and why other parents in the same situation think about these things.