Hi. I'm online and happy to answer your question today.
There is no clear cut hereditary link in macular degeneration, although there does seem, clinically, to be some sort of weak link. That being said, I don't believe that his daughter has to worry about it. If she smokes, however, she should stop.
Macular degeneration does not cause "lights out" blindness. It impacts the central part of the vision many times causing a person to become "legally blind" (vision less then 20/200 on testing).
I can not predict the future. Yet. :) but, as I stated above, your father will not go 100% blind from this. And, like you, the grandkids are fairly safe.
Thank you very much!