A.O.
J.,
My son has been going through the exact same thing! He's 5 months and 3 weeks. He used to be a great sleeper and then we traveled quite a bit at the end of the summer. So I thought that's what threw his schedule off and he'd be back in it soon. However that never happened. I even went to the doctor to see if he had an ear infection. They said he was healthy and that he's just going through the stage where he's more aware of his surroundings. So he's probably startling himself when he wakes up at night and he realizes he's alone. I think he now rolls over at night too which is causing some issues. Either he can't figure out how to roll back over or he's startling himself so bad he can't get back to sleep.
I've heard from many other mother's who have said their child went through the same thing at this age. So it's probably not what you want to hear but it's probably a phase and she'll grow out of it. That's what I'm hoping for. If you get any other good advice or find something that works let me know since I'd like to hear it as well. Good luck to you!
A.