I am in the process of buying a full stash of Petite FB. My son is 21lb, tall and skinny. Though the mediums fit him well enough, and look like they would last him a long time, I want these to be the last diapers that I "have to" buy. I can see that the rise on the mediums would be too short, and as a pp stated, the rise on the petite is a good 1 1/2 to 2 inches more. The other thing is the crutch is also wider by about an inch, meaning the larger size stuffers will fit without getting rolled up.
No matter who is president, I will live life with an open and loving heart, kindness, and tolerance of all good people. I will stand against racism, sexism, and all prejudices!