Sleep Reassurance

The title of this post doesn't refer to adult parents needing reassurance that they will indeed one day get some sleep.... though don't get me wrong, sleep would be nice.... sleep in chunks longer than 90 minutes.

We're having one heck of a time with Cori's sleep again. It's been going on for a while, and I'm seeking any and all advice on how to ease the situation. Putting Cori to bed at night has become an awful exercise in separation anxiety. It happens every night without fail and it seems to be getting worse.

No matter who puts Cori to bed (we take turns) we do out normal routine we've been doing for over two years. But then when we kiss her good night, the great need for reassurance begins. Cori will say "You're going to put your PJs on, brush your teeth and wash your face, then check on me and then go to sleep?" And we say "Yes" and she says "Okay". But instantly she will ask again "You're going to put your PJs on, brush your teeth and wash your face, then check on me and then go to sleep?" . This happens a good half-dozen times. And if I venture down stairs instead of to my bedroom, the screaming instantly begins.

If you try to leave the room during her questioning, she just keeps asking. And then about 1 minute later, she starts sobbing and screaming for "Mama". We go back, and it starts all over again. If we don't check on her (we've only tried it once because of the result) she just works herself up into a frenzy. She will also ask for me to sleep with her (which I cannot since I get up to feed Benjamin and to nurse / pump).

Recently she has asked to sleep with her light on all night (she never needed this before - a night light was sufficient). And also recently she is waking up multiple times though the night crying that she wants me to sleep with her, or she wants more in her sippy cup, or that she is scared. We ask her if she is afraid of anything and continue to reassure her that there are no dinosaurs, no bad storms / thunder & lightening, etc.

I just don't know what is driving this, and worse, have no clue how to make it better for her. I think most of it is rooted in specific separation anxiety towards me, maybe because Ben is here now and I don't have all my attention focused on Cori. Tonight my mom (who's staying this week to help out) said she'd sleep with Cori. Sure enough, Cori still was sobbing for Mama and asking repeatedly about me "You're going to put your PJs on, brush your teeth and wash your face, then check on me and then go to sleep?" . So it isn't just that she is scared and wants someone to be with her. She is very close with my mom and apparently that wasn't good enough. She kept saying she wanted Mama to lay with her, etc.

Is this a normal 3 yr old behavior? Is this driven by bringing a baby into the mix and adjusting? Is there some sort of growth explosion happening that I'm not aware of? Is it all 3 of something else entirely?? And how do I fix this? It's been 5 weeks now (started before the baby was here) and it's just getting worse.