How big is your family?

This past weekend we got to go up north with some great friends from work and stay at the Haynes' cabin. We had a blast with the Lamberts and the Haynes.
We were all talking one afternoon and Tyler provided some pretty interesting insight to the size of our family...

Heidi: Jon, how many people are in your family?
Me: I am the oldest of 3.
Heidi: What about you Kristin?
Kristin: I am the oldest of 6.
Tyler (without being asked): I am the oldest of 4!