Sister

A sister (also called 'wista', 'wister', 'sista' or 'sissy') is the female counterpart of a brother, and are extremely common in pookie-ing.

How it happens
When a pookie usually wants a sister, they go up to a pookie and ask "want to be wistas/broders?". Usually they'll say "wes!" and sometimes they'll say "mo!". If the pookie says yes, the new duo of siblings sit together and wait for adoption. When they get adopted they usually share a room.

Personalities
Usually the average pair of pookie sisters like all the same things. Sometimes they're polar opposites! Sometimes a sister may like girly things, while the other likes things boys usually will like. When using this idea, think sisters from movies and TV who are polar opposites.