Hey, good to hear from you again. I checked out your post history and wow, you've certainly been through some ups and downs.
So, is making a second FB account and doing different posts on each one "usual behavior"? Well... hard to say.
On the one hand, pwBPD struggle with a sense of self -- a sense of "I am me, and I am always me throughout time and space". I don't really know how to say it better, as I'm pretty sure I don't have the same struggle. From what I've read, though, pwBPD generally look to external sources to try to get an inner sense of stability.
So, it could be a reflection, perhaps subconscious, of her not really having a solid, single identity. Could be flitting back and forth between "versions" of herself.
Telling you about both accounts could be a bid for attention. "I feel empty... pay attention to all this stuff about me and how I feel, so I get external validation".
It is all speculation from me at this point, bear in mind.
On the other hand, as we step back from that question and get a 30000 ft view (as they say), we could ask -- OK, if that is "definitely" why she's doing what she's doing, then what do
you do with that information?
She's the mother of your young child (if I'm reading correctly), and you guys are ironing out the wrinkles of coparenting. Does this information change anything in how you interact with her for coparenting purposes? Perhaps if the accounts show your child in danger, then yes.
Otherwise, have you heard the phrase "letting people rent space in your head for free"? It's when we ruminate about disordered people, their actions, their craziness, their... um... unique ways. We're sure giving them a lot of our mental energy. And you have 3 kids to care about.
I wonder what it'd be like if, when you notice yourself going in circles about her newest wackadoodle stuff, you used that as an "alert" to yourself to do some self care, to do something for your kids, to take a walk, to wash some dishes, to listen to good music?
Also, this stood out to me from one of your previous posts:
I really need help in understanding why I still hanker for this relationship
Would love to hear more about the progress you've made in exploring this!