How are you counting her due dates? Not that it really matters, as I said before, a due date is just an average. Lots of mares go well past their "due dates," and things are perfectly fine.
One of the signs that a mare is getting close is that her belly becomes sort of v-shaped. Foals are most often born in a sort of diver-like position, front feet first followed by the head. To be oriented like that, the foal is in an almost sitting position inside the mare, and the "point" in her belly is caused by the foal's rump.
The ligaments in the mare's pelvic region begin to soften and stretch to allow more space for the foal to pass through. The mare appears to carry the foal in a lower position, and the bones on her topside may become more prominent as a result. I've heard people refer to the "starving dog" look of a mare that is about to foal, and she can look pretty rough, with her prominent tail head and big hollows in front of her hip bones.
Is Sugar starting to look like that?
