Leaving her be is a good first step. She knows she can be alone and safe in her crate and keep an eye on all you new people.
And you've figured out you need to hide to get her to come back in, that's "normal".
Just very small steps, allowing her the time (could be months) to ease into this new world.
Sitting on the floor in the same room as her crate just reading or watching TV, but with a couple treats for when she eventually comes out (and for when she will take a treat from you, or you may need to place it on the floor for her to pick up). But just providing a safe place and a calm environment will help her lots.
Thanks for taking care of her.