Very anxious 4 year old - need advice

[Sleepsleepsleep123]

My 4yo daughter has always been a good sleeper, although a sensitive child generally. I have no reason to think she is neurodiverse.

About 2 months ago (for no reason I can discern), she developed quite serious separation anxiety. She doesn't like being separated from me in the house and if I left her in the car (eg to grab my purse from the house) then she goes totally berserk. She happily goes into nursery and runs around playgrounds etc so the anxiety is quite specific.

This has gradually fed into nighttime wake ups so that she wakes all night calling for me to check I'm still there. My husband started sleeping on her floor to reassure her that we were there but this has been going on for a month now with no improvement. We have also tried making a bed on our floor and she can come in and sleep with us but she is still very worried unless she can see us.

I am heavily pregnant with number 3 so I wonder if this is what is causing the anxiety.

Has anyone experienced this? I saw on another thread that someone had this until their child was thirteen which is, frankly, unthinkable.

Any ideas or advice or shared experiences would be so welcome.

Did you have your second child in hospital? If so, she may remember you being away then. When I was expecting my third, I would often wake at night to find my 3yr old standing by the bed. The last time he did it was the night no 3 was born. It was as if he needed to reassure himself that I was still there, and hadn't disappeared in the night.

@eeddiemairswife Thank you for replying. Yes I did and I had to stay in for a week as well. She was only 21 months at the time but maybe she's retained some sort of negative memory? I'd never been away from her before that.