However...my status as having DID or at least having named parts became apparent while in EMDR examining the trigger of hating being left out of things, specifically being not invited to things, especially being the only one....SCREAM![/QUOTE

How rude, inconsiderate, & 28 other not as nice words!!

As a performance dog competition trainer, I learned a concept called dumb handler. When you want dog to figure out what the right thing to do is, handler pretends not to understand wrong behavior. If your sister were the dog, you the handler/mom would tell your daughter how much you are looking forward to girls night. Get dressed and prepare to go. Give your sister the opportunity to chose the right behavior

Congratulations on raising such a successful, intelligent daughter.