For one, I would share your trigger with your husband. Not in a confrontational form, or with any expectation that he directly does something to prevent her from being in your world. It’s more an issue to make him better aware of the consequences and the long-term effects. His response should be a combination of shame, regret, and care.
Second: If you are up to it then don’t avoid her when you run into her. She knows you, she recognizes you. You mentioned that you contacted her one night, and she knows who your husband is. You can 100% expect she’s looked you up and has at least seen your picture.
So do this mental exercise: Prepare for running into her, prepare to enter somewhere she might be. Be decided beforehand to hold your head high, act with dignity and grace and to totally ignore her existence.
I find it… calming… to have some sense of pity for those that do something wrong to me. Not compassionate pity, but more of a demeaning pity. Like… when you see her prepare yourself so your first thought might be "well… at least she’s managed to keep her leg’s together. Good for her!", or "poor lass – must still be sore from kneeling behind the dumb-bells". This thought sort of tricks your brain from the suspense, anxiety and fear it’s headed towards and makes her less of a threat. It calms you to decide your next steps.
I’m not suggesting you look her up. To me it’s your call if you find another coffee shop or if you decide to go and reclaim this one. Maybe next time she’s there you don’t turn back, but change your plans from having a seat to getting a to-go cup. But don’t let her see fear or that you are afraid of her. It’s more like she’s a turd, and you are leaving because of the stench.
I ran into the OM about a month after my d-day. Even then I realized he wasn’t my problem. Just a random guy my ex hooked up with. I was working a Saturday night and I was doing some random DUI stops. He sat in the car along with 4 of his friends and made the mistake of saying something like "hey – I f… your woman!". Somehow, I had the ability to hold back my initial reaction of pulling him out by his neck and beating the crap out of him, and instead answered instantly "I remember you! You went from a penis to having an innie in less than 2 seconds!". His driver friend was sober, and they left laughing at him more than at me.
"If, therefore, any be unhappy, let him remember that he is unhappy by reason of himself alone." Epictetus