There it is again - Pickle bag :shock: NEVER heard that term used before last week.
Anyway, no matter what problem she had last year, do not touch the udder until AFTER she calves. If she still has a problem, than you can check it out. But as stated in previous post, a 3-quartered cow can do just as well raising a calf - just as long as it isn't a mastitis that causes her to become sick. If it's a "blind teat", just ignore it.
But Bez is sure right. No reason to keep a poor uddered cow if "pickle bag" means she has poor quality teats or udder. I realize this is your son's cow, but keeping replacements/breeding stock out of a poor uddered cow can just multiply your problems. He would be better off selling the cow & replacing her.