Husbands friends.

it can be a bit tricky if they are your husband's friends.
but she sounds a bit domineering. don't be drawn in.
least said the better.
no thanks, not for me. and don't hang about after saying it.
just repeat as necessary. don't discuss, don't deviate, don't justify. use broken record method.
good luck.

Londonwifi, it sounds like manipulative bullying disguised as an invite-

I experienced similar with one of my husband's friends- After agreeing to attend a few events it was evident that the friend was manipulative, inserting herself in others personal lives- After a while I declined invites-

I don't do well, or feel at ease in company (with very few exceptions) and if I have had a persistent invitation, which has happened over the years, I've simply said so.

This is a genuine case of, "it's me and not you".

Why this woman hasn't got the message yet I cannot see.
Like you, I suspect an ulterior motive. Don't be drawn in by this arachnid.

If despite everything she still asks you, then just continue to politely decline.
You don't have to elaborate or be confrontational. You don't care about her so don't waste any time or energy worrying about her.
I imagine she'll get bored and give up eventually!

I will always say, ‘That is so nice of you to ask me to join you, thankyou, but I am not the social butterfly that my husband is, so I will politely decline’
That usually suffices when my DH friends partners ask me to go out with them.

Well you have said you've tried everything to get the message across politely, so now the gloves come off. Just smile sweetly and tell her straight you don't want to meet up. Ask her not to ask you again. Be straight but firm.