Can freezing water damage a sheep's milk bag?

Our dog went crazy today and chased our sheep around. A few have visible blood and are limping, but it's nothing too terrible. But my dog chased a Big Mama (that's what we call her) down into the creek. The weather has been so cold lately and it had a nice layer of ice on top. Big Mama thought she could run across it safely, but fell through and was stuck there for almost a half hour. When we finally got her out, she was shaking for quite some time. Do you have any idea if being in freezing water that long will have an affect on her milk production?? She has a baby that still needs nursed and I'm showing the lamb in this year's fair!!

*Thanks!!

I would call a Vet asap and ask them this question.