I have read a story like that (long, long time ago) where a girl got pregnant that way, but like the other ladies said, I think it's very unlikely. Good luck!
I agree with GRose.......possible but HIGHLY unlikely.....
First off, her never having inserted anything into herself before has NOTHING to do with the chances of getting pregnant. In theory, yes, it is possible but pretty unlikely that she would get pregnant from sperm being on her vagina. Spermies are good little swimmers but the chances aren't very high, since they would have to first off find their way into her vagina and then make their way up to her uterus, she would also have to be around ovulation time and still the chances of getting pregnant at ovulation are only about 20%.