If this was an accidental pregnancy, then you can take her to the vet and have her spayed right away and then she will not have the kittens. Especially do this if she is under a year because if she is then she is waaaay too young to be having kittens in the first place.
If you are a breeder, then she needs to go to a vet to be sure everything is going along fine and to have her looked at for the symptoms you have never seen before in pregnancies.