...as if she owned the place.

I keep looking for evidence that the new kittens are feeling at home.  Well, if this doesn't make that point, I don't know what does!  This is Grace, on her back, on the couch, asleep.  And look at the way she has installed herself!  I would say that she feels quite at home.  They are now fully integrated into the family.  I have another photo which I will have to post, showing how the kittens co-exist with Bebe, the older cat.