Maisie was Alex's college roommate. She was known to be bubbly and little dumb, as well as everything Alex did not want in a college roommate, but Haley managed to convince Alex to let Maisie stay. Alex wanted a roommate who was like her, smart, a know-it-all. Maisie had been known to make a couple of inappropriate comments, but all were done unintentionally.
In "The Storm" Maisie was studying with Alex at the Dunphy house (and later at Jay and Gloria's) where she ended up admitting to Luke that she thought he was really hot and could see herself making out with him under the right circumstances.