A girl joins a group as a thief ends up a mage. Printed before 2005

[Angela]

A girl leaves her job at a tavern by joining a group as a thief. Switches to a young man and his group entering a cavern. There is a cave in or something and he gets separated. Ends up finding the girl and the have a fling before his group finds them. She absorbs power so they can leave the cave. She and the young man wed and find her a teacher to learn to control her new power. Printed before 2005