<human>: My sister's dog (a chihuahua-dachshund mix) is about 6 months old and was pretty good about doing her business in the right spots. She has a kennel with those scented potty pads, and for the first few months she learned to use those. There was the occasional poop on the carpet, and she would prefer to poop in the other dog's kennel (a ~4 year-old chihuahua) instead of her own for whatever reason, but as long as she did it in the right spots, it was fine.

But over the last two or three weeks, she's suddenly stopped going in the right spots almost entirely. She doesn't act any different otherwise, but when we chastise her immediately (putting her nose in it, stern voice, a love tap) she seems  genuinely confused as to why we put her in time out.

She clearly proved that she can be potty trained for months at a time, and there have been no problems with the other dog. She gets a plenty of attention and sleeps in my bed with the other dog every night.

The only cause I can think of for her change in behavior is my sister recently having a baby. She and my brother-in-law don't spend as much time with the dogs downstairs, though the dogs are still almost never alone. And as far as the baby changing things, she had the baby two months ago but the dog has only started acting out a few weeks ago.

Anyway, I would appreciate any tips or insight as to how to retrain her. She was doing better when I was constantly monitoring her ( I mean constantly. She never left my sight for two days) but fell back into her ways after I gave her some space. Also, monitoring a dog 24/7 isn't exactly practical. Thanks for any help!!!

Can you condense the text into three sentences or less?
<bot>: Dog was potty trained for months and now is peeing and pooping everywhere despite little-to-no change in her environment.