Who is Catharine from Welcome to the Monkey House and what is their importance?

Catharine is twenty years old and is going to be married in a week. She is caught totally off guard when Newt tells her he loves her. She is angry, frustrated and sorry. She tells him she is honored and that she loves his friendship, but that it's too late and she's getting married. Throughout the story, Catharine is the one who keeps talking. She gives Newt all the reasons why it was wrong of him to come and says repeatedly that they need to part and just be friends. She claims to love her fiancé, but she lets Newt kiss her twice. It is not until she watches Newt sleep for a full hour in the orchard that the reader knows she loves him. When she wakes him up, however, she once again refuses him and resolves to go home.