Given how Holmes and Watson are public domain characters, I have chosen to make them better.
(Notes under cut)
Shay drinks... a lot of caffeinated alcoholic drinks. And has greying hair due to stress. They like wearing silly ties :) They've also removed all thoughts about gender identity from their brain to leave more space for crime solving.
Joy is a MD and moved in with Shay impulsively and she really can't believe how batshit crazy her roommate is. She runs a medical blog which slowly dissolves into more and more posts recording her roommate's behavior. She enjoys the occasional crime-solving, as it gives her something fun to do once in a while.