Who is Dr. Lily Sharp from Treasure and what is their importance?

Dr. Lily Sharp is an archaeologist, who is studying a village in Greenland when the charter plane crashes on the fjord. Lily and her team arrive but have a snowmobile wreck on the way, making them among the injured rather than able to help. Dirk immediately asks her out and even walks through a snowstorm to have dinner with her. Lily works with Dirk on the quest for the treasure, and she carefully seduces him early in their relationship. At the end of the story, she admits to enjoying their affairsays but realizes that Dirk is not the kind of man to marry.