I play a game online that tells me this: 2 copies of the vienna gene will act just like 2 copies of the albino gene. Both will be white, but one will be BEW and the other REW.
Since the BEW can only pass on a copy of the vienna gene, every kit will be a carrier of one copy of the vienna gene. Her kits have will a 50/50 chance of actually expressing the partial dominance of the vienna gene. Usually the incomplete dominance of the recessive gene will express itself with mismarked white areas, like a sock on one of the legs or a blaze down part of the face.
Not all vienna carriers will express this incomplete dominance. This means that a non vienna marked rabbit can still carry one copy.
Any rabbit a BEW is bred with, will produce kits with one copy. To get more BEWs, you can breed two carriers and cross your fingers that the die rolls give a buck with 2 vienna copies. A BEW buck is born.
If you get any REWs when breeding her, both she and the buck are rew carriers.