My mum had nine brothers and sisters and I actually know all their names but I don't remember where Marguerite was in the order. (She was older than Mum, though. Mum was the second-youngest.)

Everyone in Slytherin can practically reel off their whole family tree -- I could tell you exactly how Ron is related to Draco (even though they'd both prefer to pretend they're not). So I used to wonder if I had any cousins on my muggle side.

Anyway I am pretty sure I got his bracelet off for him but I don't remember anything else about him.