You must learn to join the dance

So sometime after the war when Draco is a healer he is working with someone and they mention jokingly how Draco is an only child and Draco reveals that he actually has 3 dead sisters:

Ron: Classic only-child thinking

Draco: . . . .  I'm not an only-child actually

Ron: I mean not anymore, but you were most your life

Draco:  . . . .  Kinda I had and older sister and two younger ones before

Ron:   I’m - I

Draco: Lucrezia died after a battle with dragon pox, and Cassie and Drew got caught in some muggle conflict in Belfast. My mother barely survived it herself. To be honest a part of her died too. A part of all of us did.

Hermione humors Parvati and Lavender and let's them do a makeover and they come up with this outfit <3

You know what would have been awesome!

If when the Slytherins started singing their little bullying chant “Weasley is our King,” if Gryffindor and then the rest of the school responded with “We Will Rock You!”

Vivienne and Amelie Rosier’s parents were deatheaters who died in the Battle of Hogwarts, Narcissa Malfoy then raised the girls as her own after their parents death.

Headcanon that Narcissa and Lucius had a daughter before Draco but she died when Draco was one.