It's always fascinating to me to see different takes on the Lupin parents, as well. This is one I haven't seen before, where Mrs. Lupin clearly wears the pants, especially financially. I like it, especially in regards to the romance Remus ends up getting into in canon. (They always say guys fall for girls like their mother.)

The Lupin parents have been lurking in the back of my head for quite some time -- in fact, they were some of my first OCs. I'd say Celia is more like Remus than Tonks, though I can sort of see where you're coming from.

And yes, of course Sirius is insanely smart. McGonagall says so, and since when does McGonagall give compliments lightly?