My cousin is long since divorced from his first wife. I hadn't seen her since until two years ago when it was their daughter's 18th. I and most of the family were perfectly civil with her; the day was about her daughter, not old feuds, and my cousin now has a civil, if not friendly, relationship with her after much antipathy in the early years.
The next day I'd put some pics on FB and she popped up saying how lovely they were. (She isn't my friend on there, but can see things her daughter is tagged in). Fair enough - but now she pops up every time there's a family do saying how lovely it all is and what a happy occasion. Then the other week I uploaded some old pics of my (deceased) nan, tagging family members I thought would be interested. There she was again. My nan hated her!
Today my other cousin's daughter (cousin 1's sister) turned 21. Ex-wife has posted long flowery update about 'Where has the time gone, your parents must be so proud'. To give this context, she isn't FB friends with the birthday girl - she's just posted on her timeline of her own accord. This is despite the fact that one of the proud parents - my cousin's sister - utterly, utterly despises her. Why would you actively engage in those circumstances?
I had a nosey at her FB and she has my cousin's surname listed under Other Names - yet not her maiden name. Wouldn't people who wanted to find her be more inclined to search for that than a married name she hasn't used this century (and went by for less than four years)?
She is remarried with two more kids, so unlikely she is looking for a way back in. Is this just for show ('look how civilised I am with my ex's family') or is she really wearing rose-tinted specs about the whole marriage and her relationship with our family? (As background, she was delighted to marry into a big close family at the time, but after the split we were terrible controlling people who never gave her a chance.)