Well it's surprising to read all of this, kinda seems like we didn't read the same thing. Just as you have every right to feel like that towards mc, from my eyes I kinda understand her. In her past life the one source of happiness and love that she whole wholeheartedly felt was her daughter. I think her feelings are valid, since she didn't have a "happy" love life/marriage she is more inclined towards an experience she's already had: her daughter. So to me her actions didn't seem that unexpected, she wanted to get back the strong bond she had with her daughter, she couldn't really believe neither in her own feelings nor on ML's feelings. Idk I found that aspect/arc of the story very human.
I didn't comment this to start a fight, I guess I was perplexed seeing a completely opposite view compared to mine.
She's selfish, she only thinks about herself and her "daughter" who wishes for her to be happy in her 2nd life. She' wants her daughter but her daughter wants her to be able to love her happy life with the man she love but still search for her first child which is cringe and selfish... She doesn't think about her man's feelings. She's ok with breaking his heart as long as she can see her daughter once again(who,again, wishes for her to be with ml in the next life and to be happy). I am really pissed when reading the part of the graduation ball confrontation... It irks me