Diapers may help short term, but you might want to take her to the vet to rule out kidney or urinary tract infection. Has she been bred a number of times? That could make it more difficult for her to be continent too. If the vet says she is healthy, perhaps crate her overnight as dogs don't want to dirty their sleeping spaces if possible, then take her outside first thing in the morning before her feet even touch the floor. Give lots of praise and a treat for anything done outside, and an "uh-oh" and trip outside when she slips inside. Stay outside with her until she does something you can reward. Could you take her out frequently during the day and, again, give lots of praise and a treat for anything done outside? This will take some time and persistence on your part but I hope might help you and your little girl.
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