you can work this now Cricket. I'm sure some parenting books could help you start stating what your new reality is. You just have to have the energy to stick to whatever boundaries and rules you decide to enforce.
It is very tiring sometimes, so pick carefully. I listen to Eminem's 'Not Afraid' to gear myself up.
Lately I've been observing boundary problems at my job. My two docs want our practice to keep being a 'family.' We've got one drama queen and one passive aggressive running the place. I have managed to stay out of the DQ's issues. But the PA, she gets high off being a martyr. She works like a dog being indispensable yet the docs can't figure out that is how she has them over a barrel. The rest of the team is so tired of her hourly moody cycles. She bad mouths the MDs and the staff gets tossed in a lot of flotsam. They hired in a practice manager but claimed to us she won't 'be over us.' Yeah, she can sure do a lot of change with no authority... I'm waiting for them to learn its time our family had some rules of engagement. someone needs to sit at the head of the table. In their stead, the practice manager must be given authority.
In your family, that is you Cricket. You are the parent. Your law needs to be obeyed. If you are bringing in the resources, then you demand respect. You get to take a shower and dress in peace. Flip on the light, blast some music she doesn't care for and move her carcass out.