Your age ranges are a little strange. I'm 33, which I consider early thirties, but I have young kids and stuff. I've been DMing since I was a teen.
That's why I went with Stage of Life elements too, because the ages shift a little depending of geography. Having lived in the south, the midwest and the northeast, that "married with a couple young kids and our first house" period is anywhere from early 20s (south and midwest) to mid 30s (northeast).