Going farther then second with my girlfriend

Me and my girlfriend are both 16. We have kissed..and I have felt her a few times (on top of the shirt.) I want to go a little farther by maybe going under the shirt to feel her...or possibly fingering her. Here is the problem.. I do not want to ask her about it..because it is awkward.. What kind of signs does a girl give off to show that they are horny..or want to go farther? How can I tell when the time is right? Everyone says 'ull know' but I want to know specificly how ill know.

when a girl gets aroused she will most likely make a lot of contact with you, meaning your body..if you are in the position again when you come to that point and you feel perhaps maybe she's arching her back or pushing her hips into you..then maybe first try and rub her "down there" very suttley and slowly over top of her pants..if she backs away then you know she's not ready, but if she likes it (and you'll know) then keep rubbing for a min. or two and gently try to see if she'll let you undo her pants...if she does at this point you're pretty much recieving the go-ahead...and just remember everything after this point needs to go slowly..let her enjoy it and you too. Try and be safe!. Hope this helps, Cheers.

Experienced woman