How can i pleasure my girlfriend through her jeans? please answer! iam really stuck!?

my girlfriend likes to direct my hands down to her vagina and leave them there (as though iam to make the next move) but she does this in public places (like in clubs and at the movies when we are kissing) i guess the question is more.... "is it possible to pleasure her through her jeans" because i have no idea why she would put my hands down onto her if it wasnt possible... lol i know its a stupid question (iam totally not experianced as you can probally tell) but her hints arnt exactly suttle lol