jacannah
Hello
From your post, I am assuming that there are more than one female, and that these females are all laying eggs (?).
Are there any males in the cage/flight?
If there are males, I would remove them to another cage.
That said, your girls might still lay eggs, whether there are males around or not.
Zebras, can start reproducing at a very early age, so six months is not unheared of.
If there are nests in the cage, I would remove them, along with any nesting material, that could be used to construct a new nest.
This may stop the egg laying, although some determined girls will start laying eggs in seed cups, or even on the floor of the cage.
Your other alternative, is to leve the eggs where they are, and let them sit on them. This at least will give their bodies a break from the constant laying (as in, the more eggs you remove, the more eggs they will lay).
Another important thing, is to make sure that they have enough calcium in their diet, to compensate for the loss through egg making.
Something else you can try, is to shorten the light exposure to less hours a day, by covering their cage, tricking them into thinking that it's not breeding season.
I would also add a swing, and some items that may capture their interest, and perhaps take their little minds of 'just' laying eggs.
Goodluck.
~Elana~