Grooms mom driving me insane

This past weekend my mom hosted a shower for us. It was really lovely and everyone was having a good time... aside from my FMIL...



back story : a few months prior- after unexpectedly losing my dog to HSA, my fiancé and I opted to adopt a dog who was scheduled to be euthanized for no reason other than he was covered in burns. Although we have our own house and have been financially independent for years - this sent our FMIL into a frenzie.. a few days after we picked our new pup up my FMIL texted me randomly and I mentioned the adoption- only to be sent a series of messages saying how stupid of an idea that was, how she was in shock and disgusted, how we are going to enter into a financial crisis and lose our house, what a stupid name we gave him, and how I intentionally hid this from her, forced her son to hide this, and how we acted in spite of her since we didn’t consult with her... I wish this was something new but unfortunately every choice we’ve made over the past six years has been blown into this sort of mess (getting an apartment, getting a dog, buying a house.. etc)... and everytime she is hurt and a victim.. this time I chose not to respond.. my fiancé tried to once again reenforce boundaries and tell her for the 5th time that we didn’t appreciate being berated and she needed to remember the choices we make are between us... so she blocked him

fast forward to the shower: we hadn’t talked, when she arrived she kept her back to me the entire time. I tapped her on the shoulder, reached in for a hug and said “hi, how are you?”.. she said “I’m okay”.. rolled her eyes and walked away... She found a seat and kept her back to me the rest of the time, fine. Every guest who tried to introduce themself was met with a dismissive attitude or a snarky comment -including my mom (I.e one of my bridesmaids greeted her and she said “hm, didn’t recognize you with makeup and without daisy dukes or every man staring at you”.. uncalled or and inaccurate ) .. come time for gifts, she sits directly in front and turns her back entirely to us- talking loud to a friend she had accompany her.. she turned around once to give my Fiancé a gift to open .. a pair of socks that said “for your cold feet”.. she laughed and left, all while yelling at my fiancé’s father .. “is this how it’s going to be at the f’n wedding too?” ... there were 70 people so I chose to ignore it the best that I could but five unrelated people came to myself, my mom, and my fiancé to ask what was up with her... my fiancé spoke to his father and he expressed that his mom was hurting and needed an apology because to add salt to an already open wound (adopting a dog) we also failed to announce her entrance and bring people to meet her .... we were surrounded by people the entire time and were both dismissed by her...


Am I missing something ? I feel so confused and stressed out .. I honestly have no idea how to handle this