As far as I know there are no shots you can take to avoid Hep C, just the precautions listed earlier. I have been with my hubby for 15 years and we have been careful about
not sharing personal items, but I have not used rubber gloves...I have them, but he doesn't have bleeding problems...yet.
I would think the grandchildren should be educated about not getting grandma's blood on them...(I don't know a good way to do this without it sounding like grandma is "contaminated" Not having children we haven't had to deal with this issue.)
The more your brother in law educates himself, the more comfortable he will be with the situation.
So sorry you are going through this and good for your Mom giving up the drinking. Be sure to let her know how proud of her you are for doing so. Can't have been easy.
Angie1953