Well technically kitten and puppy is just a label put on food. You can feed adult food and they will be just fine. You just have to feed MORE of the adult food perhaps but theres nothing special in them

Secondly, maybe this will show your dad you need to get her spayed. Explain to him that now not only do you have to care for Oreo, you will also have more kittens to deal with. And you can't just stick up a "free kittens!" sign because who KNOWS what lunatics will reply wanting a "family" kitten, right??

I just hope the best for Oreo throughout and after her pregnancy and hope the kitties are all born healthy!!