VM means the offspring would have a 50% chance of being a carrier. Your doe might not even be vc at that point. Unless she's produced vm or bew the odds of your kits getting it could be 50% if she is vc or 0% if she isn't. Usually that is just stated as a 25% chance of being a carrier but that's not entirely accurate since whether they have any chance depends on if the parent is a carrier. You can't mark them as anything really unless you know at least that and even then you can't mark a guaranteed carrier from a carrier or even VM without them producing VM or BEW offspring themselves. Since the vm does appear on the pedigree it's really all the proof of possibly carrying a gene that anyone usually provides or pays attention to.