Quentin and Catriona are, I think, the most nuanced parents in all of DWJ, because they genuinely love their children, are doing the very best they can, adopt Howard more than once without being asked or rewarded till Howard gets around to the reward eventually (without telling them), are making a teetery but still functional living doing what they love... And they still fuck up a lot and are completely out of their depths, sometimes in ways anyone would be in the circumstances and sometimes because of who they are as people. They feel three-dimensional to me, not just the sort of parents one gets in rollicking adventure/mistaken-identity/kind-of-heist-flavored middle-grade books.