No they are kept in a smaller separate aquarium, but I am afraid that by using the state net to fish them or just by the mother having it that they can have it too.Are they kept with the parents?
If yes, you will have to treat them also because if the parents passed the worms into the tank, it will also affect the fry.
But for fry, you will have to be careful with the dosage and not to overdose.
As far as I know, Praziquantel is safe for the fry.
But for other medications, I am not so sure.