I have one of each. DS was born 7'8 and was 25lbs at 1. DD was born 6'11 and was 22lbs at 27 months. She is now 4 1/2 and I am thrilled she has hit 30lbs. I lost a ton of weight quickly with ds, continued to lose until I weaned him, that was the thinnest I had ever been. DD I lost weight very slow and not all of it. I'm wondering if ds was just better at getting to the hind milk.
My son was. My DD didn't really care at all about nursing...she wanted to eat and be done. My son, would spend HOURS on the boob if I'd let him. He loved it...he WORKED ON the boobs! I really think he got at a lot more hind milk, his technique was crazy. Very different from DD.