Good points as usual, Rose. I know people who say their mom is their best friend, things like that. It took work to accept that I won't have that kind of relationship, ever, but over time I have made peace with it. It is what it is, as they say.
From what she has mentioned at times, my grandmother was very critical of her when she was growing up. Sadly she has repeated the pattern.
And, yes, she is extremely insecure. She's the thinnest-skinned person I know, unable to handle the most minor criticism. Interestingly she has always loved to tell me I am the over-sensitive one. Projection, I guess.