Hey Aiden, I didn't mean to be offensive. It is probably my background too. I work hospice right now, so I am around a lot of debility and age stuff. I'm glad your grandma sticks by you, she sounds like an outstanding individual. As for your granddad - that's the kind of old man I hope to become, although I now perfer to have my horses started by others.
I think the point about a new life and yo being part of the old life is very perceptive. She may be hoping to drive a wedge between your father and you. I don't know why , but my step mother did the same thing - and gender/sex wasn't even in the air at that point. I think it must make the women feel powerful or in control or something.
Good luck talking to her, and perhaps talk to your father too.