Nah, Jenny, none of those scenarios is ringing true. She has 16 grandchildren, teenagers down to a newborn and doesn't have time for any of them and really never has. We spent *loads* of time with my grandparents as children and loved it (as all kids do) so I feel sorry for my own kids. She told me once that she doesn't do much (anything) for me because I "have a good husband and she didn't". That is supposed to explain why her parents helped her in ways that she is unwilling to do for me, such as babysitting when I have doctor's appointments or driving me to the airport or attending my kids' Christmas pageants, etc.
Up until now, I sorta held out hope that the real reason she was like this was because she didn't want the kids around my dad's drinking--I didn't either. But he is gone now and I see that as a bit of wishful thinking. She hasn't slowed down on her grandiose vision of herself wrt her career and still has no time for us, really. However, she is making noises about perhaps getting another job and so maybe that will allow her to refocus her priorities.
