It's compassionate to foster cats from a shelter.
Katie has just visited the shelter, and she feels bad for the cats there.
Katie wants to encourage people to adopt.
Katie adopts a cat from the shelter and shows it off to her friend.
Katie suggests to her friend that she should adopt a shelter cat.
Katie's friend is inspired to adopt a cat from the shelter as well and multiple cats get good homes.
Katie's friend is skeptical and doesn't end up adopting so the cats don't have a proper home.