She was never really supportive of my relationship with my fiance even if we aren't a toxic couple. In fact, she was the first friend I introduced my bf to back then. She was chummy with him at first, but eventually I felt that she was cold to him and I just sort of went through the years without making a deliberate effort to make the 2 of them bond (plus i went to study overseas, then COVID happened, so I didn't really get to go out much).
When i posted the proposal pictures online, she didn’t congratulate me. Instead, she called our third friend (she was literally crying, according to the third friend), saying things like she’s angry and hurt she didn’t know about the plans before it happened. This “friend” chatted me too to ask how the proposal went, but it didn’t feel genuine. She said things like she thinks I’m “not rational”, it’s “too soon”, how will the guy sustain my lifestyle, where will we live, etc. She even brought up the past, like how I couldn’t even decide if I wanted to sit with her back in prom (I don’t even know how prom is related to my proposal). She also secretly messaged my sister (who she never talked to) asking how my fiance is with my family. I stopped talking to her because I felt like she really crossed a line. It seemed that she wasn't really concerned about my welfare because she couldn’t even point out any relationship red flags—just all her outsider opinion on my relationship she wasn’t even supportive of. I found out from our common friend that she’s still upset at me, and has no plans to apologize, because in her opinion, my fiance and I wronged her.
I know I should be focusing on the positive (like our many friends and our immediate family members who are all happy for us) but sometimes I’m reminded of how she ruined the experience for me. Any thoughts on her behavior, and advice on how to move past this?