If a cat cannot nurse her baby kittens, how long will it take for her milk to dry up?

My Cat had kittens about five days ago and they all died of Neonatal isoerythrolysis ( Feline NI ). Its a disease that kittens develope after they are born a different blood type than there mother. she was type B blood and the babies were type A. When kittens nurse off their mother the first 24 hours, she releases calastrome (antibodies, immunities, Etc.) that their gut in their intestines absorbes and it helps them not get sick. We did not know this at the time and we let them nurse off of her..... Their bodies absobred the Type B calastrome and it attacked their red bloods cells and they stopped thriving and they went into renial failure (organ faliure) and they slowly died one by one. It was tragic and it hurts to think that something so innoccent can go through all that pain. : ( My cat is really depressed and of course is not taking it well. She is really shakey and her nose is not wet half the time and i just hope that if her milk dries up she would get better.