When they said Yin Fen was made of vamp venom, I couldn't help thinking of Sizzy... Maybe the show's going to use her Yin Fen addiction to make her want Simon. I know it's a bit weird, but... π€
If there's a ship I wish the show would completely change / change up it's Sizzy. There's nothing interesting about them in the context of the show - it's even more unbelievable that someone as hot and ~cool~ as Izzy would bother with Simon. Just as it's unbelievable with Maia but I'll bite because their chemistry is quite sweet if dull. There's no way it will make sense that at some point Maia, Clary and Izzy will be vying for Simon's love (going by the books). The character is beyond basic as is the actor, and all three of them can do much better.
I'd much rather see development into non-creepy territory with Aldertree for Isabelle or the introduction of an entirely new character for her. If they do insist on Sizzy they shouldn't bother with it until season 5 or so. Maybe by then the sheer development of both characters will make the pairing make sense and somewhat compelling.