Hello and welcome to the forum
It sounds like you're getting really tough nights at the moment ((hugs)). I'm not surprised you're exhausted
Can I ask for a bit more detail about what you do when you go in to her? How long does it take to get her back to sleep, and is there anything which finally makes it happen, or does she just sleep eventually (until the next time)?
Also, please could you post her day in the following format so I can see if anything stands out on that front?
WU: What time does she wake for the day?
E: What does she eat, what time?
A: How long is she awake between sleeps?
S: What time does she sleep from and to?
And repeat til you've covered 24 hours
I'll also warn you that while I completely understand why you bring her into bed at 4ish, it *may* be re-enforcing the night wakings, so as exhausting as it sounds, we might have to find an alternative to that. There are some BW techniques which can help with that, though, especially if there might be elements of separation anxiety at play.
Out of interest on the SA, is she showing much of this during the day?