How long have you had her?
If she isn't yet comfortable to come out of her litter box and explore the rest of her cage, then it isn't advised to take her out of her cage. That's rushing her (and stressing her). Leave her be for awhile.
Give her time to get adjusted to her new home/cage.
Once she's comfortable in her whole cage and is consistently potting in her box, then her cage door can be opened so she can hop out if and when she feels ready. The area around the cage should have an ex-pen so that her space is limited. This way she can return to her cage and litter box at will.
I'll link a site when I get to my main computer, but she should not be picked up out of her cage. That will teach her to fear you. Let her take the lead as she feels ready.