I think it would be an absolutely horrible mistake not to follow up with someone about this.
Life with a person with serious issues can be pretty horrible, and sometimes nearly impossible to extricate oneself from. Do not do nothing. Only someone who’s never suffered would say that.
You, because of your history with her, should not be the one to get involved directly if there’s an issue. However, if you suspect a problem, I’d suggest letting someone you truly trust who is an objective Halachik authority decide on the next move. The one exception to this is you might need to consider where you’ve gotten this information from and how reliable it is when you speak with a rav and give him that information.