Thanks for the reply Jann. She has mated. I've heard it's usually around 30 days but she's been quite anxious, has drastically reduced her eating the past couple days and is determined to get out of her cage.
I have had females lay at 25-28 days. it is possible for early arrival. You may try a different bin or even the trash can method. Make sure she at least 8-12" of dirt, preferably 12". Make sure it is easy for her to get in and out of, bird ladders made a huge difference for mine. Afterwards she will hardly be able to walk horizontally, much less vertically. Keep that food and water ready, as she will need it ASAP!