NAYRT I love the tiny nerd and ship her with many characters, but I never really thought about smut for her and I think you're right that it's partially because she very much has a "Steven's little sister" vibe. Not to an extent where I'm squicked by romance with her and other adult characters, but I definitely feel more like I'm shipping a character from a kid's show than I do with say, Jasper or the Diamonds.