I would get her sugars checked.
And rather than punish kids for accidents, in Early Intervention we teach parents to reward kids for their successes. Put up a sticker chart. After so many stickers, they get a prize. That sort of thing. It's worked with many behavioral kids. The kids who have the biggest problem are the ones with parents who make a big deal out of everything. Kids like a big negative reaction sometimes... it can be fun to have that kind of control over their parents.
A side note: Also, about the second birthday thing, some kids just aren't anatomically ready at that point. They have to be aware of what they are doing and able to control it somewhat. A lot of 2 year old boys and some girls are not physically capable of that.