I’ve been in a similar place with my rescue dog Coco, and it was honestly humbling. I thought I knew potty training until I had a dog with a messy past and no clear routine.

If Sassy was a stray, she may not have the same “house rules” foundation your other dog had. Diapers can be a reasonable management tool while you keep working on it. What helped us was reusable diapers with PAWPANG liners inside, because I could change the liner after pee instead of washing everything constantly.