How much ventilation, and where??

[Dragonisme]

It looks totally fine to me! It looks like they have ventilation!

 

[rosemarythyme]

Follow up question. The girls are about 7 weeks old. Once this is done, can they go in it without worry about cold? It’s getting to about 50 degrees at night.

Yes, they'll handle that temperature fine as long as you've already taken them off heat. And down to freezing is no problem in winter as well - you still need plenty of ventilation in winter too.

As far as ventilation, at a minimum you want to aim for 10% of floor space or 1 sq ft per bird, whichever is greater, but in hot climates you'll need more.

Best set up for hot climates is having at least one side completely open (you can tarp over part of it for winter if needed). Ideally that would be a side with roof overhang to protect it from the elements, and faced away from predominant wind direction. So with your build you could probably leave the "top board" that you have in the last photo off and replace it with wire mesh (assuming that wall doesn't face into oncoming winds/storms), or possibly the top half or one third of the walls on both sides, where there's a little more roof to provide coverage.

Also need to point out, chicken wire isn't very predator proof. A raccoon or dog can easily break through or pull it apart. Hardware cloth or welded wire would be more sturdy.