From Pinterest: Have you guys thought about having any kids?

Sonic: Shadow said he wasn't ready to be dad...I don't blame him

Shadow: Being the Commander For G.U.N is hard at it is...and Sonic would need all of my attention if he is pregnant

Sonic: and Its not that Tails would be there to help me...but he has a kid of his own...and a wife

Shadow: Maybe in the near future