OH MY GOSH!!! The thing you said about projection! That is LITERALLY what she does! When I was on honor roll, she thought she was stupid. She would constantly go around pitying herself, then she started calling me out for being stupid for the simplest things! When I had lost 26 lbs and she was heavy, she started to call me fat!
She still does that crap, but thank you so much! I will look into this!
They do that projecting to make you feel emotions they can't feel and to feel less anxious. In some ways we all do this, but we correct our behaviour, they don't. They can get violent too (throw a tantrum), so don't push the point on what they are upset over. Just got see that they are not well mentally themselves.
Can be seen like a cat playing with a mouse for amusement.
Very primal instinct that we all have up to age 7 and then mature emotionally and stop doing that. They don't mature emotionally past age 7 and get worse as get older. I have seen women, men into 50's + still acting that way. They learn to conceal it better to blend in, but is still there if know how to trigger it.
Also, YES! She did want attention from her parents. That, in part, was the reason she got jealous of me, in fact, My oldest sister gets jealous when my mom takes me out to lunch. I have also been very close to my parents and they didn't like that. I learned that just last year, that my oldest sister was jealous of me being close to our parents. (I'm the closest, but that's because I never thought I was cool or edgy for not hanging out with my parents. Smh, they blame that on me!)
You have your answer as to why she is acting that way. Once know why, learn how to deal with it better (manage it better).