If you feel she's not going to damage things for you and your social position is established and strong I'd just ignore and do exactly what you want to do.
If she asks about "whatever" just don't reply. Your OH and others (her partner too) probably know what she's like so you don't need to be the fall guy.
I think some people go through life phases when they need lots of attention/validation and need an audience and someone to listen to their stream of consciousness.
It may also be an anxiety/ND thing, where she needs to just let loose on someone in an intense way?
It's really really not your problem, she'll have to find another outlet. If she gets upset she'll have to self-regulate.
This actually reminds me of someone who was at a dinner event I attended.
She was "essentially" polite and there was nothing exactly offensive she did.
but every single aspect of the conversation was steered towards praising herself, or bigging herself up.
Eg - she was asking me how much I worked out, then pointed out her workout routine was better than mine and the gym had asked her to be an instructor 🙄
She wanted to talk about her appearance just like you'd expect an ok looking well dressed 53 year old to look.
She said her husband (who OF COURSE was so attracted to her in her casual clothes) didn't like her getting dressed up and going out.
I wasn't sure if was male jealousy, suspect he didn't want to get caught up in her competitive attention-seeking routine (!).
It wasn't actually damaging just kind of funny and a good night overall, but I would NOT want this individual as my close friend messaging me.
This was a Meetup for new people btw.
We were hardly the most glamorous of audiences!
So I think that the fact that she was a local woman who had to find a new group of randomers to talk AT meant that her old friends were probably a bit sick of her!