Doodler, that's great input, and interesting you put it that way. My IC says she will try not to focus on my W too much, but it's important to understand that there are probably other factors at play in my sitch. While she "disclaimered" it with "I'm not a licensed Psy.M.D, it sounds very much like, given the familial genetics, and the behavior of my W, she is very much teetering on the edge of an issue with BPD or DID.
While I'm certain there was a "mixup" between the groups, when I spoke to W over text about it, and informed her she was talking about one of my brother's friends, and not me, she replied "bullsh1t, she said she talked to "<myname>", not <hisname>, I think she would know the name of the person she's texting"... (she's got a good point... but this makes me think that if there is multiple minds going on in there, one would be hearing "she's texting someone in my brother's group", and the other would feed it the manipulative value of "i heard her say <myname>"... so while the comments could be partially true, it only takes half of what she needs to hear, to feed the other half of what she "thinks" in completing her validity.
Also, one of her friend's could have said "are you talking about <myname>?", and she just wasn't paying attention and said "yeah, his brother" or something like that... who knows. but it's funny you bring up BPD and/or DID within hours of my IC bringing it up.