Breastfeeding

I have been breastfeeding my daughter for about four months, and other than the typical setbacks everything is going great. She has recently started to grab thing....including my breasts when she is eating. I have red marks and bruises all over from her grabbing. I've tried to make sure I am on top of cutting her nails but that doesn't seem to be helping. Has anyone else gone through this? What can I do to make her stop? Thanks ahead!