and David arose and went, he and his men, and killed of the Philistines two hundred men; and David brought their foreskins, and they gave them in full number to the king, that he might be the king's son-in-law. Saul gave him Michal his daughter as wife.
So I don't know what kind of a daughter she was. I don't know but he figured she'd be a snare to David and give him problems, which she did in time.