4x8 is rather tight for 16 birds....unless you live in a mild climate.
All those things help.
Glad she fit back in.
Oh, and.... Welcome to BYC! @bjm287
Where in this world are you located?
Climate, and time of year, is almost always a factor.
Please add your general geographical location to...
How big is that in feet by feet?
Dimensions and pics would help here.
Do you have a wire crate that you can put into the coop?
Best to have her in the crate 24/7 with the flock for at least a week.