I wouldn't say there is anything wrong with it at all. Everyone needs time to themselves, just because you have a family doesn't change that. I finish work around midnight and I enjoy being able to come home and do my own thing for a couple of hours before going to sleep.
Ha, I even have my own room in the attic with my stuff. A men cave, but I'm the wife and my husband controls the living room. It was a demand for a new home from both of us: I need my own room.
That is really not a normal thing in the Netherlands where homes are small. I do my crafts and such in it, I do have a painting set up for the kids, but they visit in my room and have to ask.
It's wonderful!!
I also work to midnight and enjoy an hour alone in my own room at the end of it. And a few hours in weekends.
Today we are married nine years. Putting up your own boundaries to stay sane is very good marriage etiquette.