A girl of the Latter Day Saints faith between the age of 19 and 21. Generally, these girls are extremely attractive because their men dominate this religion and therefore have more authority to tell their women what to do-- like lose some fucking weight. Also, women of the LDS faith worry a whole lot about marriage, so they take extra care to make sure that somebody (a Mormon guy) will want them physically. Since polygamy used to be allowed, the guys would only fuck the pretty bitches and tell the others that they had to cook and clean. This made the women genetically prettier.
Since the Mormon dudes are on their mission for 2 years, and these girls are in their sexual prime, they are really fucking horny for a dude their age to come around and give them a poke.
Often, though, Mormon Molly's will only do anal, for fear that they will pop their hymen making everybody know that she fucked a non-Mormon dude.
These women were all once Mormon Mollys: Ann Romney, Katherine Heigl, Kelly Packard, Juliane Hough