More of a WWYD really. Sorry if it's long!
My best friend and I have been friends for 6 years. We have both been with our partners for around 4yrs and we are all friends, often doing things as a group. My partner and I got engaged about 6 months ago and my friend initially seemed happy for me.
However, soon after she started being distant with me. Cancelling plans (including a weekend trip I had paid for, without enough notice for a refund/take someone else), ignoring texts and being generally really off. We went for about 8 weeks without seeing each other. For context, we live in the same town, and usually see each other every other week at least.
When we finally met up, I asked why she had been acting the way she had and she denied it. Later on in the evening, she got drunk, admitted she was jealous because she always expected her and her partner to get married first as they have been together slightly longer (4 months more). She then started to cry and said her partner hasn't proposed "when he said he would" and that he keeps "dragging his heels" whenever she mentions marriage. In the end she agreed that a lack of a proposal was something she needed to discuss with him and that we would forget about how she'd behaved as it wasn't worth falling out over.
A few weeks later, she went back to ignoring calls/texts, cancelling, being very cold when we do speak, etc. I have asked her a few days ago via message, if everything is okay and said I'm always here if she needs to talk, but she has ignored it and sent back something about the holiday she is going on in a few months.
She can't be sick of me talking about the wedding as I only discuss plans when people ask me about them, and she hasn't.
I am worried about her as she has never behaved like this in the past, it's a complete personality shift. However, it is really starting to get to me because I feel like she is taking the frustration she feels toward her partner out on me. AIBU to feel like this or should I be more understanding??