I do not know if this will help any but this is what we plan on doing:
On the day we find out the gender, I am going to make a very small cake in the color of the gender and have the center filling between the layers the same color. then I am going to frost it completely in pure white frosting. I am then going to give it to my 15month old. And record as she destroys it, and reveals the gender then share it on FB for my family and friends.
I am not sure if that is too elaborate for facetime. The other thing I was planning on doing was buying a black balloon and filling it with confetti in the color of the gender, and popping it with my 15month old. Which I ruled out, because it would probably scare her.