Katherine is the friend of Austin. They have been friends since they were high school.
In Homescrapes she found a cat on the street. She thought it was Austin's cat so she knocked on the door. On the other story Austin was in great panic trying to get dressed and looks for his clothes. When Austin opens the door. He warmly welcomes her and thinks that the cat belongs to him. Austin then told that he'll take care of the cat and explain it's not his. To which Katherine leaves.