Poking about the Lexicon, I find Sinistra. Pretty much nothing is known for sure except she teaches Astronomy. Is that too little to go on to pick a House?

Lexicon also lists a Tracey Davis on the classlist (which I never heard of). But, she wasn't mentioned in the novels. The Lexicon mentions Daphne Greengrass, pureblood Slytherin who took a practical OWL with Hermione.

I have to admit, I'm fascinated by pecking about the Lexicon. I'd never heard of it before! This is amusing me.