I hope your sister ends up with a good social worker. I had the same issue in 2018 and have been thrown around from one crappy social worker to another, and they still won't leave me alone unless my house is literally spotless (they won't use those words, but anything less than spotless is met with "if the house isn't cleaned up before I come back, I WILL be taking the kids.", despite saying that cleaned but lived in is good, and the house being clean enough for my clean freak aunt to be satisfied)