It is udder edema, fairly common in dairy cattle. It will subside in a few days or week normally. And all the other posters are right. She is a dairy animal; made to give milk....alot of milk. She either needs more calves nursing her or you need to be milking her. If her calf only nurses one quarter, because it is getting enough milk from that one, or even 2 quarters, the other ones will swell, get hot, get mastitis and you could wind up with her getting sick or at the least ruining her udder by the quarters not being milked out and eventually drying up. Get her in a head catch, give her some grain and either get her milked at least once a day or put other calves on her. The best way to get her to take them is to put her in the head catch until they go right for the udder, and not letting her have her own calf to nurse except when they others are nursing. It's an all for one or none thing and most dairy cows will allow other calves if they get the relief of the pressure.
Why did you start with a dairy animal if you were not planning to either milk her for your own consumption or to use her for a nurse cow?