S3, E13: While Marissa does all she can to get to know her sister again, Kaitlin (recurring guest star WILLA HOLLAND) just stirs up trouble for the gang as she prepares to celebrate her birthday. Meanwhile, Sandy encourages Seth about college, but Seth finds a better alternative. Sandy and Matt (recurring guest star JEFF HEPHNER) work together to secure a contract for the new hospital. And Julie continues her quest to put her family back together.