At 3000g, it is highly unlikely she is having 6 or less eggs. It's impossible to say by looking at her how many she will have, but 3k girls can easily have more than double that. You may want to rethink your incubator system all together to something more suitable.
This is my suggestion for a cheap and easy way to go without having to find a broken fridge (or a truck to transport it): https://www.youtube.com/watch?v=eUIRtUFjgfQ
Walmart was selling a similar model cooler (actually slightly larger) for $69 when I was there. It doesn't have the lips the exact same size/way that Garrett mentions to fit his boxes, but you can just make a little frame out of light diffuser and zip ties so water circulates and the tubs have something to sit on.