Yes and no. Scalzi's daughter Athena is at an age where she's not necessarily going to be enthralled by books that her parents read and recommend. She's in her mid-teens, after all.
The world has changed a lot, too. Some parts of Heinlein probably seem less relevant to the next generations than they did to us, for reasons I mostly like. For example, most of my nephews, nieces and godchildren wouldn't understand how ahead-of-his-times Heinlein was when he portrayed women working professionally, because it would never have occurred to them to question a person's ability to do particular work on as irrelevant a basis as their gender. The views Heinlein expresses about sex in Stranger in a Strange Land and later works, which I found shocking enough that they put me off Heinlein for a few years when I was a teenager, don't shock them or even sound particularly strange. They're still a bit young to understand the deeper stuff -- all the material that shows Heinlein as something other than just a popular writer. Fortunately "still a bit young" means that they'll probably grow into it.
. I tend not to give RAH to teenagers - they haven't learned to think yet, but early twenties when idealism and intellect combine seems to be the best time.