It was a sticky situation, really. The whole point of Sam and Dean’s work was that they killed and hunted monsters. It was their job. So when you were bitten and turned into a werewolf, moral dilemmas arose.

Before the two brothers could make a decision, Rowena decided to take action. She helped you get away. It wasn't that she didn't trust the boys, but… well it was that she didn't trust the boys. Not with you, not a friend she unadmittitadly cared for deeply.

You needed Rowena’s help. Being a Supernatural created wasn’t easy. She found an isolated cabin in the woods, getting it open and helping you to the couch, the bite mark still causing issues of pain.