Oh, I liked this. I like that everyone involved has softened and come to accommodate each other (even Lucius, even if his Slytherin mind is still working on ways he can work things to his advantage), not in any way that makes them less or makes them hard to imagine out of the characters we knew. Actually, I think it makes them stronger, every one of them, to have come to a place where they clearly can manage to work by building consensus (with each other, or not, but my sense is that all of them, even barely-seen Narcissa, are heavily interested in not having another damn war, which is a pretty good incentive to learn to get along.
I love that you gave Lucius and Narcissa another child, both because it maybe does sort of foreshadow that Hermione will say she can wait, and because I sort of like to contemplate what happens in a family that has raised one child in one fairly determined way, and has an enormous change of circumstance in which to try the same game differently, if that makes any sense. I like that you gave Scorpius a sister, too (I may have done that before because I just want him to have one, darn it. Heh).
I would love to one day read the story of how this Hermione and Severus danced about each other until they figured out how to get down to business (which I am confident they would, probably with a non-insignificant number of stumbles and/or moments of snark), but that's not a complaint about the ending point you chose. I'm just sufficiently invested in this setting and these characters as you show them to hope one day you want to tell me more about them.