Just give her time dear. I've had a cat that hid under a couch for a week when I first brougth him home.

Give the cat alternate nice comfy and private places to sleep, with in her sight so she knows they are there.

Put food and water at the edge of the bed, to hopefully coax her into coming out into the open more often.
And just hang out near her and talk to her softly is all, just be reassuring, she'll come around.

Good luck!