I have 2 cresties that i got about a year 1/2 ago. both about the same age, babies. they have always been housed apart. as adults i can tell for sure the smaller 1 is female. I wonder about the larger 1 as it looks female but is stocky and 56 grams . the smaller 1 is 32 grams. What is this difference in size? they are kept and fed identically