Courtney Milan is a hell of an overachiever. She isn't content to write charming romances in which, as in Austen, the primary barriers to love are the uncontrolled aspects of multifaceted personalities. Milan also strives to remind the reader of how many different kinds of love there are, and that loving thy neighbor is hard, but worthwhile. She is Dickensian in her examination of class, but so much broader in scope. But also fun. They flirt with math. How adorably geeky and STEMy is that?
If they weren't so much fun, I might be tempted to call them uplifting. They are, often, deeply moving, because her characters have sometimes horrible, albeit too believable, backstories. Her happy endings are hard-earned.