Its also hard because she seems like shes a lot better but its probably all an act. She isn't in therapy or anything.
After 5 months? I doubt she's better. At least in terms of her overall mental health.
If anything, I wouldn't be surprised if she's now "better," as in she has further "honed her craft" as she has learned from more experience. They can & do build up their "skills" like that.
I've run into one after several years. I, too, thought at first that she had gotten better. It certainly seemed that way.
I eventually learned that she had only become a more adept actress.
If you go down that slipperly slope of contacting her & mentioning that you have a new GF, this could possibly open a whole new can of worms... . as in, she could try to figure out who & possibly meddle with the few interested girls that you mentioned. Do you really want to run that risk? I know I wouldn't.