When my female went into heat the first time, she started losing hair, not bald spots just hair would be on the floor. We thought maybe it had something to do with her being in heat but we took her to the vet and he said she was probably allergic to beef protein and to change her to lamb and rice food, we did and it stopped, she hasn't lost any more and that's been almost a year ago, so if I were you I would definitely take your baby to the vet. Good Luck. Hopefully it will be something simple like ours was.
Paula
Halle
Brutis