IBCLC = International Board Certified Lactation Consultant in case anyone is wondering
You should talk to my wife-- Shelly--on my friend list. She takes the IBCLC exam in July also... and you've got the whole family member with diabetes thing in common... She may not know the specific answers but between the two of you you might get on the right track faster.
I could tell you, but it's a pretty controversial answer...so I won't. :)
Has be been tested for the various MODY/monogenic forms of diabetes? I know these can manifest at an earlier age.
Wow, I have no help to offer, but I am just always amazed at how parents manage babies and toddlers with T1 (I was dx @ 3 myself). And I laughed when reading your post because my first thought was "I wonder how many carbs are in breast milk?"