I would say founder, has she been on green grass or anything that can cause that. My recommendation would be to get her to the vet asap. It is best to get her some drugs to take down the inflammation in those feet before there is too much permanent damage, the worse they are the more the bones in the feet start to rotate causeing permanent and irreversable damage. Hope she feels better soon and take her off of the grass if that is the case, and feed her grass hay.