Congrats on the eggs - the mis-sexing of snakes is something I think almost everyone on this list has experienced! Hope your little female has laid all she has in her and recovers well. Best of luck with hatching the eggs.
Lisa - Probing is definately the most accurate means of sexing (other than having a snake lay egs - that pretty much confirms it!). Popping is accurate with babies, but she is too big now.
If you can post photos of her tail - one taken from underneath and one from the side, from the vent to the tail tip - we should be able to give a good guess. The tail of a male is longer and doesn't taper as rapidly after the vent. There are some good comparison pictures in Kathy Love's book The Cornsnake Manual.