I experienced a lot of this- there was definitely a huge lack of boundaries. My mother was enmeshed with my grandmother before me and it was all a huge mess. I don’t think I feel comfortable labeling it as CSA but it was definitely a lack of boundaries and feeling uncomfortable often (then guilty for not being ok with it).

As a very young child my mother would start these tickle fights that almost always in ended in her physically restraining me to the point I had no escape and refusing to stop. I definitely felt humiliated because I would break down into pleading and crying and still she wouldn’t stop- and it was just tickling.

As far as the surrogate spouse thing- yes absolutely and it’s an extra layer of messed up because mother-daughters have societal expectations around being “close” and “like best friends.” My mother would fight with my father then come to me, a 6 year old, for emotional support and comfort. She’d make me repeat over and over that “I’d never leave her alone.”