Livin' in Utah
Hey there,
Here are some things about (good) Mormon girls that are college age or above. If you want a LTR with them, it's in your best interest to be Mormon as well. Getting married in an LDS Temple is stressed from day 1 of a Mormon Girl's youth, and only Mormons (in good standing) can get married in the temple.
You may not be looking to marry her, but another principle taught is that you should only date the types of people that you plan on marrying (aka other Mormons). Not every mormon girl adheres to that principle because girls will be girls and date the coolest/hottest/funnest guy instead of the nice mormon dude. There are Mormon AFCs.
However, with such emphasis on marriage and family in the LDS faith, there is some backlash. And fortunately, not every Mormon girl is looking to get married ASAP.
Living in Utah, it's not uncommon for 18 year old freshman at BYU to get engaged within their first or second year of college. It's also not uncommon for a couple to get engaged within 6 months of dating.
This next portion has no scientific backing but from my experience with Mormon girls, I've gone out with about 10 mormon girls in the past year, and 2 of them were more one or two dates, and I'm friends with female co-workers and neighbors who are mormon as well.
Some things that can help you see if a Mormon girl is rebellious and the higher chances of hooking up:
If they watch rated "R" movies, that is a sign that they could be more rebellious. Some mormons are so paranoid about rated "r" movies that they'll only watch them if they're on TV or rented from a video store that edits movies.
If they drink caffeinated beverages (i.e. Mountain Dew, Coke, Red Bull, Coffee, etc.) On BYU, you cannot find a caffeinated beverage; they even serve caffeine-free Barqs root beer in Utah.
If they drink alcohol, that's a huge sign they're rebels. Caffeine is frowned upon in the LDS world but acceptable; alcohol is a definite NO-NO.
Find out how many guys she's made out with. Since mormons are christian-based, chastity is a big thing. If they aren't virgins, they can't marry in the temple. Temple marriage is important, read above. So in the regular world, it's the number of guys' they've slept with, but in the mormon world, it's the number of guys they've made out with. SEX is a NO-NO, but Making Out is a personal judgement call. I know of girls that are waiting to kiss a guy until they're engaged or until they're married. And I've met Mormon girls that have made out with 40+ guys, and they're only freshman in college. At BYU, there was an acronym NCMO (Non-committal Making Out); it was frowned upon, but it still happens.
Those are just some things I've noticed about Mormon girls. There are obviously exceptions, every girl is different, but from a basic guideline, I think it's pretty good. If she's a devout Mormon and intends to stay that way, the farthest a non-mormon will get is a consensual make out. If she's devout but a little rebellious, your chances of going further than making out increase.
You should ask her if she's ever heard of NCMO (pronounced "Nick-Moe") and just tell her you heard that at BYU it's well-known and ask her what she thinks of it.
BobbyJ
And just to clarify, Mormons used to believe in multiple wives, aka polygamy, but is no longer practiced, except by rogue/fundamentalist mormons. These fundamentalists are not endorsed by the LDS church and are not in good standing with the LDS church and state government.