*cough* Er, yeah... Officially.
With a bit of fanfic-ification and some minor xml editing, the current run has Amy and Sophia being Emma's kids, your Cousin Amelia and Cousin Sophie. Raised in France and a British boarding school respectively, they share an adjoining apartment in the Vault, so as not to intrude on their mother Emmanuelle and her absentee lesbian sugar mama Yumi.
This is the dark tale of Amelia trying to escape her mother's whorish lifestyle, working two jobs to raise the money to take her little sister away from these bad influences, only to fall into the clutches of her amoral cousins and tumble down a rabbit hole of slutty ecstasy. So tragic. So beautiful. J'appelle ça de... l'art!
Edit: As if the name Emmanuelle wasn't displaying my affection for last century French 'Art' films hard enough... lol.