Try giving HER some more attention GHoST.

Play her at her own game lol. For a 17 year old (I so hate using age as a generalisation) to be in a relationship and not see sex as a issue is like me walking into a pub and ordering an orange juice.

It seem's to me that you like this girl almost to the extent of love lol.

I think if you stick with her long enough and still see other friend's (but not show any tendencies to play away (as it were) then you will eventually gain her trust and she won't be so paranoid.

Sorry if this doesen't make sence I'm as stoned as John Clease in the life of Brian.