I actually was a Giants fan when I was 9 years old, back when they beat Denver in 1986. Christmas of 1987, my dad got me what he thought was a Giants Jersey, but it was a red white and blue #12. (The Bills and Giants jerseys looked so similar those years and it didn't have a name on the back). Once I had the jersey I decided that the Bills were the team that I was going to root for. The following year the Bills are in the AFC title game against the Bengals and I have been a die-hard ever since.
I guess what I am trying to say is that I could have been a Giants fan, but my dad totally screwed me over and it is totally his fault that I am a Bills fan, but I guess it was meant to be. Let your kids root for the Giants if they want to - don't make the same mistake that my dad did, it is a much better life.