Because of your ages the wouldn't be any rape charges but you could potentially face a charge of sexual abuse in the third degree which is a misdemeanor. You jurisdiction does allow for a defense in you case if you can establish that you really did t know her age and that she lied to you. If you are being charged with a crime you should speak to an attorney as soon as kpossible and not try to go at this alone. If you are still in the army you may wish to consider speaking to a JAG officer, s/he may be able to assist (though I don't know that they would represent you in a civilian court).
I would contact a competent criminal defense lawyer in your area ASAP. I assume you have not been arrested yet. There are several sexual crimes in KY that are relevant: KRS 510.010 through 510.150.
KRS 510.020(3) states a person is deemed incapable of consent when she IS LESS THAN 16 OLD. You have a statutatory defense in KRS 510.030 by a defense that you did not know she was under 16 and could not legally consent. Get counsel ASAP!
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..