If he is going to have time alone with the child I think a medical diagnosis would be important. If he is indeed having seizures and collapses, is he capable of being responsible for a child?
Your daughter has a lawyer, I'm sure he can help her with whatever she needs to do to protect herself and her child.
Now hand me your detective badge, mama, I have quite a collection that began with my own.
I found more peace when I spent my time putting what was right into my life than when I spent it finding what was wrong with my son's.
Hugs