How To Dry Up Cats Milk?

I know it sounds weird but you have to nurse off of the cat

I have been searching the same thing and have found a consensus that says to let nature take it's course.  They should dry up on their own and as long as there is no signs of infection she should do fine in a few days to a week.  One vet answered that if you fasted the cat for 24 hours only letting her have water during that time and then half rations of food the following day, it should help dry her up.  There is a medication to help but the vet said it has it's own side effects.  If your cat isn't in pain and doesn't show signs of infection, it's probably best to do nothing and let nature run it's course.