Can animals have more babies if they don eat the afterbirth or is that a myth?
The only reason animals eat the afterbirth is for the nutrition. That way they don’t have to leave the kittens to hunt for food for the first few days after they are born. Since you are providing food for your cat, she doesn’t actually need to eat the afterbirth at all. Whether she does or not will have no bearing on her ability to become pregnant in the future.