Rule Number 1 when dealing with a pet: If you do it once, and they like it, then it is a RULE!

You have now allowed her to sleep in your bedroom. RULE!!!! She will insist on always being in there at night. Hope this is what you had in mind, ha ha haaa!

Leaving her, well, you are not talking about addressing separation anxiety. She had bonded with you folks big time, and is afraid to let you out of her sight. She's been without you, things did not go well (her prior life). She needs to learn she can cope on her own. You may want to Google: dog separation anxiety
as you will find plenty of hits on how to work on this.

I'm not sure which link to give you; you will see they have methods if the dog barks, if the dog scratches at the door, if the dog allows you to leave the room but not go outdoors, etc. So I'm not sure which set of training tips will be best.

I think you are fantastic owners, willing to work with this girl, doing things step by step. Good job!

BTW, most separation anxiety takes about 2 weeks to work on and see progress.

Oh yeah, can't leave without saying: silly man, thinking he can do something BEFORE he lets the dog out!!! Ahahahahahaaaa, he will learn!