How did Cassie's feelings toward Suzella differ from the rest of her family?

The Logan's are entranced by Suzella..... she's a beautiful girl, which tends to make Cassie jealous. As a result, Cassie asks what can be perceived as inappropriate questions. The more Cassie's family loves Suzella, the angrier Cassie gets. Suzella, however, wants nothing more than to be Cassie's friend.