I'm going to refuse my grandmother's inheritance.
Why would you refuse an inheritance?
My grandmother is suffering from dementia, so she might not realize what she's doing.
I understand that you want to do the right thing but your grandmother has chosen who to give her inheritance to. You should respect that and accept your grandmother's inheritance.
A family fight is worth it
If you are sticking up for your grandmother, I get it. But that money will just go to someone else who is willing to take advantage, you care about her and will respect her money.