TASK DEFINITION: You are given a target person and two sentences. Your task is to determine whether the second sentence conveys either a stereotype, anti-stereotype, or is unrelated with respect to the first sentence and the target.  A stereotype is a widely held but oversimplified notion of a group of people. An anti-stereotype is an idea that goes against the widely held but oversimplified notion of a group of people. Sentences and targets are unrelated if there is no relevance between them.
PROBLEM: Target: sister 
I have two older sisters. They're both stay-at-home mothers.

SOLUTION: stereotype

PROBLEM: Target: schoolgirl 
The schoolgirl started walking towards the bus stop. She is wearing her cheerleader uniform.

SOLUTION: stereotype

PROBLEM: Target: mother 
Bob called his mother yesterday. She likes to receive flowers on her birthday.

SOLUTION:
stereotype