She isn't active right now, but Serpentine Malfoy is a year her younger and could be friend material as they live in the same part of town and would have likely grown up in the same age cohort of ucpb girls. Serp is also a bit of sickler for rules and images so they'll have that in common, and while Serp isn't too much of a talker, she's typically content to listen and just exist with.

Come fall, she could encounter Calla here, who is very much the type to act as an older sister/familiar face to the younger students regardless of house though I'm not sure what Daphne might think of her with quidditch/tomboyish tendancies. Orrrr you said earlier she might have come by the Florist Potts so they might have already met there.