Hi! Mity here is your sister. I know we established they didn't get along at first and Mity was at Hogwarts for a bit of their growing up - Mity was a fifth year though when Mal was a first! she has come around to her in the last 20ish years but the exact relationship is to be seen. As a whole Mity takes her role as second eldest pretty seriously and tends to mother the other girls though she still can come across as blunt and rude sometimes but at this point would probably kill for each of her sisters even if one on one they aren't besties.

Octavia Fawley was in the same year, Beatrice Daphnel was a year younger but left after fifth year, and Iziza Noel graduated the year before but was two years older do to the halfbreed ban. None were in the same house though. She might have run into Iziza if she ever watch a case she worked on or tried to interview an associated client!

My only hurl option for her would be Anthony Delaney who is just an overly sweet teddy bear.