I agree that the mini Rex is a good rabbit to show for beginners. Do you have a county fair to show at? Do they auction off livestock? The reason I am asking is if the 4-Hers can auction off their market animal, you might be interested in raising California meat rabbits. They are white with black ears. Our county requires that the kids breed a doe and buck together and the babies are raised to show and sell at the auction. It is a great way for a kid to raise money for college. My daughter has been in 4-H for 11 yrs. She has done meat chickens for 8 years. She has won reserve champion for 4 of those years. She would make anywhere from $285 to $400 for her reserve champions. Even the ones that didn't win, she would make around $125 for two meat birds. Not a bad deal and the 23 at home she sold mostly to family members that wanted fresh chicken for $10 for a 7 to 9lb bird dressed. She also shows fancy chickens and lambs too.
If your 9yr old is small depending on what kind of chickens you have, I would suggest some sort of bantam. They are easy to handle for the beginner. 4-H is a great way for kids to develop responsibilty, teamwork and sportsmanship. Even if the kids don't like doing rabbits or chickens, there are all kinds of projects from sewing, cooking, woodworking, shooting sports, the list goes on and on. I hope 4-H becomes a household name for you, as it did mine and has been for 15yrs.