Putting her back with the flock would be your decision. You would need to determine if she is well enough to defend herself since she has been removed for a while. Sometimes a separated chicken is not welcome.
If it's a nice day and she will do fine with your temperatures, then you may want to at least take her for a visit and see how it goes.
If it's a nice day and she will do fine with your temperatures, then you may want to at least take her for a visit and see how it goes.