I think time is what your new bunny needs most now =) It’s great that she has a safe hiding place. It can take a long time before she ventures out of it and starts investigating her new surroundings, but that’s normal for a rabbit. Right now she doesn’t know if her new home is safe or not. Offering her yummy food is a good way of making her feel comfy. Don’t give too many treats though, buns have sensitive stomachs and a tendency to become fat, and for those reasons they should mostly eat hay (not fill up on treats so they don’t eat their healthy hay).

Cardboard boxes are great for hiding in, rabbits also like tunnels. Cat tunnels or the thick cardboard cylinders that are used for casting concrete are good. You don’t have to buy the most expensive stuff, because rabbits are quite good at destroying stuff (or bunstruct, as they themselves call it). Cheap fleece blankets to dig in are often popular as well, although watch her closely at first so she doesn’t eat the fleece. If she happens to ingest a little bit of fleece or cardboard it’s not a problem, but she mustn’t outright eat it.

I think ultimately it just comes down to time. She needs to learn that you are not a threat so continue talking calmly to her, hand feeding treats (but not to many! You can even hand feed pellets) and being patient and she’ll come around

A rabbit has a deep-seated need to feel safe and secure in their surroundings, especially when they’ve moved to a new environment. That’s why I’ve always tried to provide at least one hidey box for my pair, no matter where they are; at home, they have no fewer than three, two on the upper level of their condo/cage and one that’s set up overnight in their X-pen enclosure when it’s erected (they also have a long cardboard tunnel, originally a concrete pillar form, that I got at a local hardware store). Their cage has a solid, nubby plastic floor on the bottom level (easy to clean and provides good footing) and is carpeted on the upper level, and their X-pen enclosure has a large sisal rug from IKEA. Try only giving your bun treats a couple of times a day, perhaps as dessert after meals. I refresh my buns’ hay twice daily in the litterbox and provide extra in an attached hay rack so that it’s always available; they have good eating habits and often go straight for the latest hay refresh first even when their morning pellets or evening greens are available.

That is awesome that she’s that comfortable with you!! I get my flooring at 5 Below because they have the exercise mats that connect like puzzle pieces.