You can only decide yourself if you want to meet her and talk. But do you really want to be in a vulnerable situation whereby you could breakdown and admit how you think/know your husband feels about her having heard him admit he loves her but can’t articulate in what way?
Do you want to admit you were so shocked at how your H got over emotional at her wedding that you had to pretend you weren’t feeling well and that you needed to leave?
How are you going to talk about the uncomfortable feelings that you’ve had for years about their close ongoing friendship. Then tackle the issue of your H and her having a relationship just prior to your wedding.
She’s just got married. It all goes back to your H’s feelings for this woman “Bet”. Do you really want to discuss “Blanche with “Bet”?
Or do you want to hold your head up high and assimilate over time how you feel about all of this and what strides your H makes to convince you that your marriage has a future.
Your H has been messaging her on honeymoon, she returns and then you have personal talks with her. Surely the point is that everyone needs distance (albeit they are work colleagues).
As others have said you really can’t be asking her to maintain her distance. You and your H need to demonstrate this is the way forward.
It’s just crazy and deluded to think that the group and friendship dynamic can return to what it was. Well I suppose it can if you fully accept that nothing is going to change and that you will continue to feel uncomfortable about their friendship, but with extra bells and whistles on now knowing the conversations you have had with your H about his strength of feelings towards her.
So much of your problems stem from how entwined she is in your lives and friends. I’m really not sure at all that I would want to invite and involve her more in your deep personal anxiety. She’s been there too much and now is the time to create some distance not draw her further into your marriage problems.
But down to you.