I ask because I really don't know anymore and following a fight and some information coming to light, I've now a decision to make regarding our relationship.
Our relationship has always been about control, for her. She says jump, I say how high...I've always been scared to say no or to disagree with her but I don't know why. For some reason I'm terrified to "fallout" with her.
I would say my childhood was possibly abusive but I'm so conditioned that I don't really know. I remember being really scared of her as a child, she used to scream at us all the time. I remember being hit a lot, not just smacked but hair pulled by the scalp, siblings hit with coat hangers etc.
When I was 16 she tried to kick me out several times for no reason, I didn't drink, smoke or sleep around. I was a model school pupil with a long term boyfriend. Luckily his mum took pity on me and let me stay with them loads. I remember going home one day after being at his to find my stuff all in black bins bags on the side of the road 
I never did find out why but she eventually let me home, I suspect my boyfriends parents intervened.
Anyway to present day and I have my own family and I had quite a good relationship with her until recently. She keeps telling me I use her when asking for any sort of favour or support. She tells me I've ruined her life and she needs time to herself now to work out who she is as she spent so long being a mother.
Today we spoke on the phone and she started screaming abuse down the phone at me for no reason, well because I dared to challenge her. I didn't swear, raise my voice or anything but she didn't like it.
I think I'm confused as I'd forgotten a lot of my childhood and she had been supporting me with my own children, she's been the doting grand parenting. I'm not worried about her mis treating my children as I'm always with her when she has them plus she went on to have my little brother 15 years after me and he had a very loving childhood in comparison.
I just don't know what to do, the abusive phone call today has tipped me over the edge. I don't think I can have her in my life. I've since found out some things from relatives which suggest they were very concerned about us as children hence a lot of intervention on their part. I don't know how to process this or where to go from here :(
I was never hugged as a child or told I was loved (think she first told me this when I was mid 20s!), it's a miracle I'm so affectionate towards my own children....
Sorry this has been long, just needed somewhere to offload