Politely leave.

You politely decline her offer and tell you just wanted to swing by and say hi. You try to guilt trip her by telling her you would love to see more of her later though, and she seemed really nice.

Jessie seems disappointed for a moment but then smiles once more telling you that you are always welcome here.

You discover to your surprise that it is almost time for your next class and so you head to your room to collect yourself before going.