They really loved each other, and their children as well.
My mother had “Nicholas and Alexandra” sitting around the living room when I was a young girl: I remember dusting it! I have no idea if she ever read it; it could have been a gift. She prefers fiction to histories, in general.
They were a very loving couple and devoted parents, although she was quite a flake in a lot of ways. Still, they both - and all their children - showed the right stuff when things fell apart. The stories of Nicholas cutting wood and making repairs with Alexei, when they were in custody, are very touching.