Really Old romcom

When I say old it had to be like 50s-60s old.

working woman was getting fired from her job and as she was going home she sees a baby basket outside an orphanage, when she tried to bring the baby inside she was mistaken for the mother and she gets stuck with some random baby and is trying to get rid of it. I remember the baby helping her get her job back and I think she ends up marrying her boss?