(((Marian))) Clean and sober are just part of recovery. I've known LOTS of addicts/alcoholics still having "using behaviors" LOOooooonnnnngggggg into recovery. It is still part of the "ism" and is the REAL work in a good recovery program.
I am glad she is sober, but it will probably take running into (or over) other people's boundaries before she "gets" that she also needs to behave like an adult in all areas.
Refusing to watch the kids past 8:00 is not unreasonable. If she can't meet your boundaries, she can find another care provider.
((hugs))