Welcome to pet talk.
Not all cats will adjust immediately. I have had several just like your new meezer. They hid for weeks when you are "looking" but at times when they feel safer, they roam around to learn their new environment. Do not worry about such behavior. Finding your cat's "weekness" will go a lomg when to winning her love. With most cats it is some type of food. You can coax them out and reward them with their treat. Works great. Also keeping her environment calm and quiet will help her adjust.