1) Kids grow.
2) They won't care.

Scott

As a mom of 3, when we built our pool in '08, my eldest was 5 feet 2 inches. Our pool is a sock shape, with the heel to toe area being 27 feet long and our sports area. The original specs were 4- 4 1/2 -4. The pool digger was the one who pointed it out to me that the depths were too much to play in. At the deepest point of 4 ft, on a six foot person, that depth will hit them just below the pecs. He recommended 3.5 -4- 3.5. I am soooooo thankful we went with those depths. Our eldest is now 6.1 at 16, our daughter is 5.8 and the youngest is 5.7. It is the perfect depth.
The top of the sock to where it joins the "foot" is the deep end for diving and the torpedo lane. We went with 9' deep.