vitaluna, glad you're here.

I'm sorry for all you've endured. It's ok to not like your kid sometimes and it's 100% fair to want to protect your wife and yourself and your other kids. You can and you should.
So, what do I do with a girl like this?
It can help to learn their triggers. Holidays and trips are triggering for pwBPD. My MIL will find a way to make anyone's birthdays and holidays all about her, and if they're not, she'll make them miserable for others. My BPD daughter always dysregulated on trips.
It can also help to understand how easy they are to invalidate. There's an awesome article in the tools tab above about validation, highly recommend it. I read it often.
She probably is trying to use guilt to get you to give her money. It's a tactic pwBPD employ because it's worked for them. You made the right choice in setting a boundary with her, in fact, I think you've made some great choices in your communication with her.
I try to remind myself to set a good example for my kids, and teach them (by example, if nothing else) that guilt trips, setting ultimatums, and throwing tantrums are very ineffective ways of relating. By setting boundaries, communicating well, and being caring, patient and firm, you're still mothering, in the most responsible way.
