I don’t have an answer to your question about them moving back home, but I just drove 7 hours to fetch my about-to-be 19 year old daughter from college for spring break—and I’m still absorbing the realization of how much she’s grown and learned and changed in 9 months on her own. It’s beautiful. We talked non-stop on the way home, and I am just marveling at her.
More directly to your point about messiness, for what it’s worth, my girl was similar upon leaving but adjusted to her small college single room that no one cleaned but her. I’m not worried about that anymore!
All best in establishing a beautiful connection with your girl!