If you have enough people to keep an eye out, and someone who's always prepared to bail into the water after her, and clothes to keep her warm and dry... I'd do it. We take the kids out paddle rafting with us- three of them. Works out well, we just have to have a basic safety talk and make it key that they listen to everything we say.
If your girl can understand basic safety commands like "get down" and "hold on" she should be fine. The one time the kids didn't listen when we said to get down, our girl got thrown out of the raft. Less than two seconds in the water (not even exaggerating), but it was enough to scare her into listening a lot better. We tend to sandwich the three year old between us when we're paddling through the rougher stuff.
Bottom line, if you're comfortable on the run, confident you're not going to flip, and have enough people go for it. But be realistic, your two year old can't swim-- be ready to jump in.
Oh, helmet. Make sure she has a helmet.
It's a good day to be a duck....