Congratulations! Button chicks are absolutely adorable. I just had two buttons hatch chicks two days in a row, one hatched 10 chicks, the other 7, so it's definitely not impossible
And this is the second time I get chicks(still have the 6 that survived the first time). Mine are in an aviary(140 cm by 200 cm or something like that) too, though it's in an old barn, not outside. I suspect aviaries improve the chances of them incubating their own eggs - being able to move away from whatever scares them probably has something to do with it.
As I understand, you have two pairs in the same aviary. I don't know how large the aviary is, but if the other pair stays away from the chicks and their parents, I guess it is fine. However, my chicks have no sense of who their parents are. They will go hide under any quail they see. In my case, the 'targeted' quail has been fine with this and started helping taking care of the chicks, but this might not always be the case, so keep a close eye on them.
Apart from making sure the water is very shallow as someone mentioned, you also need to make sure they get feed with a high protein content. I don't think you mentioned what you are feeding them? In my case, I feed a game bird starter with 25% protein, but an even higher protein content is often recommended. And I grind it in a coffee grinder to make sure the pieces aren't too big.