Hello! Welcome to the forums! Aw I'm so excited for you and your new addition!
Just take your time and be patient with your bird. Changing homes is a big deal with lots of new people, places and routines to figure out. Greys CAN be fairly change adverse, so it's usually best to work at the birds pace. If she seems confident enough then let her out. If she is visibly scared or anxious then let her settle in for a day or so.
Wing clipping is a personal preference. I believe the owner needs to make that choice based on the bird itself and the environment they are in. My bird, Alfie, is fully flighted- and I am super cautious about doors and windows. It works just fine for us and I've never personally had a reason to clip Alfie's wings.
If she is already able to fly then you might be taking a bit of a risk by trimming her wings as she might try and launch off as normal and drop like a stone after a trim. So long as she is safe and family members are careful about doors and windows then you should be able to keep her fully flighted. If you do decide to trim her wings then I would suggest a VERY light trim in the first instance to let her get used to the change. Otherwise she could potentially injure herself if she falls or crash lands.