what is your mattress height?

[gcampbell72]

I am using a 6-year old crib given to me by a friend. Although I have the mattress at the lowest setting, my 9-month old can already reach all of the way over the top rail (with armpits/shoulders over the top railing). Is this normal? Is there a standard depth for crib mattresses on the lowest setting? Would anyone be willing to measure the depth of their crib with the mattress is on it's lowest setting?

Thanks so much. I know that my son will eventually be climbing out of his crib, but it just seems a little soon for him to be able to reach all of the way over the top rail.

Thanks so much!

Cathy