Hello, may I ask how you are going to get het back in her cage ? Is she finger trained, will she step up?
Letting her out will cause the others to become agitated and they will want out as well. Be prepared to be in there for a while and have not commitments .
Also it is a good idea not to let her out if it is near dark or night time, budgies do not have good night vision. Please let us know how things go.