Unpopular opinion but I don't think she is "mentally ill" in the sense of needing in patient treatment or that we should feel sorry for her. It's really tiresome to see the modern stance of "muh mentals" as an excuse for being a selfish, self centered, insensitive, entitled, dirty, bitter, jealous, angry, big mouthed, liar, codependant, obsessed, arrogant, bitch.
She only went to a psych ward in her teen years because like the selfish cunt she is, she made up a story about taking pills to kill herself to manipulate her family. She was not in an "in treatment" facility as a teenager, she was in a place because her family couldn't handle her incessant lies and being a selfish bitch. She will never change and never learn from her mistakes because it is everyone else's fault. She will never go to therapy because they might tell her she's wrong.
Just because she rages or cries or complains about the fall out from her poor choices in life, doesn't mean she is mentally ill. Having normal days of feeling down from life events or being nervous because you have to do something unfamiliar, does not mean you have "depression" or "anxiety". She throws psychological buzzwords around to suit her excuses. Even Freud said "Sometimes a cigar is just a cigar".