How can I get my girlfriend wet/horny over text?

Hey everyone my girlfriend and I have been together for about 5 and a half months now she is 15 and I am 16 and although we seem young, we are very madly in love with eachother. She is also my very first love. We are both virgins and we both want eachother to be our "first" we have talked about it but never went in to detail. And the fartherest we've gone with eachother is only kissing and making out. We've texted eachother almost everyday since the day we've met. Since school began and wentout we have become a lot closer to eachother. And now that it is summer we both have made it clear that we both miss and really want eachother ;D lol. And I want to make her something she'd never expect from just only a few text. I have tried, It was really late at night and we were both sending eachother somewhat "naughty" text. She: "what are you doing" me: "laying down ofcoursee" she: "that's all?" Me:"maybee" she: "What is it. Lolz?" Me: "thinking about youu" she: " what about me?" (I also asked her earlier what she was doing before she asked me and she was also laying down) me: "well you know sometimes when you say your laying down I like to imagine you in your bra and shorts". she: "oh really? Me: "yess ;D". Then later on she ask "what are you doing" I say "imagining you" she: Lol same imagination or different?" Me: there's been a slight change" she: "and what is that?" Me: you might be missing your shorts" she: "your being naughty ;D" me: "ohhnoo you want me to stop? ;D" she: Lolz noo ;D..and then eventually she asked if I was still "imagining her" I say yes but it is a bit naughtier/dirtier then she says oh and okay then things start to get kind of akward and weird. So if you read all that you see that she has shown that she can be "naughty"and somewhat "dirty". I mean I don't want to force anything on her I love her too much too even try. I mean I just think she is too shy or just doesn`t know how to go along with it. and sorry for writing so much lol