Hi MichelleW
BPD is quite a challenging disorder and I'm glad you are looking for ways to best manage this situation. What would you say are the main challenges you are facing?
You mention your soon to be fiancée's ex wife is an undiagnosed high function BPD. Why do you believe she has BPD, what are the BPD traits you see in her?
Does your soon to be fiancée (congratulations by the way!

), also believe his ex wife has BPD?
Take care and welcome to bpdfamily
The Board Parrot