Well to me, the fact that her husband harbored a pack of killers within that house for more than a year, where evil magic soaked into to walls, in addition to the fact that they were under constant threat of death + the fact that she was attacked within these walls and now her son refusing to continue the life that she planned for him, would throw the first 15 years within she might have been happy in that house. So yes from my understanding of cannon, Narcissa has no true attachment to Malfoy Manor.

Going worse, right as I said I don'T see her as the type to pull a wand on her son, and she did try to manipulate him. Since he has finally grown a backbone he was more aware of it than before and that is good. The Mummy thing is more my own feeling, I don't like it when grown up people use the term, because it feels like either they are making themselve smaller than they are to pacify their parents, or it is a slightly mocking element to it. I love my mom dearly, but calling her "mummy" would never cross my mind. I did that when I was five not when I am in my thirties.