husbands INSANE ex😒

Ok so, a little back story, my husband and I have been together 6 years, married for 3 and have two kids together. We met at college and are still so in love❤️ Before me he was with another girl lets called her Jane for 4 years, they lived together but she was really dramatic and would break up with him constantly. So after like the 20th time she broke up with him for no real reason he decided he was done and didn't let her come back after she was over her tantrum. When she found out he wasn't going to take her back she was really shocked and kept begging him to take her back, he declined every time and his family convinced him to not give in because they didn't like her. About 8 months later he met me and we fell head over heels for each other and things moved pretty fast. We moved in together and were really happy. When his ex found out about me she went crazy. One year she found out where my birthday party was going to be and showed up there to try convince him him to dump me and get back with her. I was so upset and he felt so bad but I get it wasn't his fault. But that's an example of the kind of person she is. She would continue to text him about how they were going to end up together and eventually "have their happy ending". He ended up changing his number because she wouldn't stop. This continued for 4 years, she would somehow always find a way to contact him or run into him (we live in a small town) even though she was blocked on everything and I was baffled as to how she was doing this. She eventually moved out of state but she would stalk my Instagram even though I declined her follow request and just kept following me even though I kept declining the request. So here we are 6 years on and apparently she's STILL not over it. Today my friend told me that Facebook offers a feature that lets you see all the places your account has been accessed from. So when I told my husband he had me look at his. And what do I find? That a computer from the city and state his ex now lives in (she's the only person we know who lives there) has been accessing the account every few DAYS. She's been logging in to probably read his messages etc. I am freaked the hell out. He said he had never once told her his password the whole time they were together so he didn't think to change it when they broke up. I'm so bothered by this. Of course he has now changed his password etc but how the hell can she still be so obsessed? I know for a fact they aren't in contact, he can't stand her. I just can't believe someone can still be this obsessed after SIX years. I'm so tempted to contact her and tell her we're aware of what she's been doing but I have a feeling that will just fuel her fire😩 what would you do?