Charming Six Degrees of Separation

[Ellory Pendergast]

Robin Goode interacted lots with Malvina MacFusty
Whose brother is James MacFusty
who would have been at Hogwarts around the same time as Caradog Weasley
Who's Catherine's husband

Wilder Avery & Eavan MacKay

  

[Odira Potter]

Wilder plays quidditch with Tegan Carstairs
Who is in quodpot club with Pandora Winterdowne
Who is Eavan's cousin!

William Pendergast and Melchior Gambol

  

[Ellory Pendergast]

William is whatever this relation is called to Faustus Prewett
Who heads the DMLE department, under which Archer Gambol works
Who is Melchior's brother

Rosaline Bennett and Andromache Pettigrew

  

[Lucien Renaud]

Rosaline Bennett is employed at Hogwarts,
where Phineas Black is Headmaster,
and Phineas used to employ Andromache Pettigrew as a governess.

Lucien Renaud and Cecily Gallivan

  

[Ellory Pendergast]

Lucien is Tristan Michaud's cousin
Tristan bangs Rasmus Mohr
Who is a teammate of Cecily's on the Ravenclaw Quidditch team

Thomas Spore and Topaz Urquart

  

[Lucien Renaud]

Thomas has a sister, Josephine
who attended Hogwarts (presumably) the same year as Evelyn McGonagall (both born 1854).
Evelyn is the sister of Balthazar Urquart,
who is Topaz's father.

Balthazar Urquart and Evie Virgot

  

[Clayton Ross]

Balt had Isis House built in Irvingly
The town in which Evie Virgot lives.

Esther Holmes & Harry Inkersoll