I've read that all kittens need deworming. The mother cat, however, was dewormed early in her pregnancy (before we knew that she was pregnant). She is now an indoor-only cat. So why would her kittens need deworming? Do they?
Not always do kittens ~need~ worming. The best advice I have to offer you is to take a stool sample into the vet for analysis and if they don't have worms, then don't worm them.