I've heard you ought to know someone through each season before proposing. I think that's a decent statement.
Personally, I wish I'd waited a LOT longer the first time around, but I was young and dumb.
Women are scared away just as easily as men are (if not more! as in, "too good to be true, so he must be a psychopathic puppy-kicking murderer), so yeah, I agree with others...she will drop hints.
Good luck! I proposed once and was turned down (still together though). It was painful, but I grew from it. So either answer will be ok, though I know you are hoping for an affirmative