Rosie was Jaylene's best friend. They had known each other quite literally forever. Their moms were best friends and were inseparable. So when they had their kids, they vowed they would be best friends as well. Rosie probably hated the couple most out of everyone. Why? She's in love with Jaylene. She always knew they'd end up together. That is, until she met Matthew.

Rosie obviously hated Matthew with every fiber of her being. She had felt Matthew had taken away the love of her life.

Rosie was purely jealous of Matthew. Not because he had Jaylene, but because Jaylene loved Matthew. Rosie could see it in her eyes. She wanted nothing more but for her to be happy, but her jealousy would always take over.

Rosie had to admit though, if Matthew hadn't taken her girl, he would've thought he's pretty cool. He might've even considered Matthew as friend material.

Matthew doesn't even like Rosie. He knows how she feels about Jaylene but for her sake, he tries to get along with her. Matthew knows how much Rosie means to Jaylene, so he tries to befriend Rosie. Rosie, of course, turns Matthews offer down and tells Matthew to leave Jaylene alone. Matthew, obviously doesn't listen.

Rosie tries so many, many times to break the couple up. She would cause the couple to fight. When Jaylene was mad at Matthew or fighting with him for any reason, Rosie would encourage her anger. She would try telling her things to try to keep her upset at Matthew. Most of the time, her plan would backfire considerably and Jaylene would go right back to Matthew.

Rosie would try to subtly bring up the idea of the couple breaking up. She would say different things to them of why they should break up, but there was that main thing she would say to the couple, which was the same thing everyone says: "You're too different."