Overreacting?

I’m 31 and husband is 35 and been married almost 2 yrs and with a baby. Since we have been together 3yrs, I have noticed this girl ALWAYS liking my husbands posts on fb and they did date very briefly right before we met. He said they never slept together but did kiss. Just friends now, he broke up with her. I know she messages my husband because he told me before about how she was pregnant with some druggies baby and he was in rehab and apparently venting to my husband about it. I asked him why she felt the need to tell him about her personal life and he shrugged and said he didn’t really know. I blew it off because honestly, I don’t think she has nothing on me when it comes to looks or lifestyle choices. But My husbands family is very tight knit with her family, like extended family type relationship.

Anyways, I notice this chic is always “liking” my husbands posts on FB so yeah I’m kinda keeping tabs on her(call me insecure idc). She never likes posts with me in them but always “likes” pics of my husband or our son. She got brought up in conversation the other day because we saw her at a store and she waved at my husband. I told I think she still has a thing for him and he said it doesn’t matter(like oh well for her, type tone). Now fast forward tonight I’m working 3rd shift at the hospital and something made me go look at her profile and I notice my husband has liked recent public pictures of her! Now I’m fucking pissed. And want to tell him to get her off his fb now and give him an ear full. Am I crazy for being insecure?! Thoughts?