When she starts to dig do not let her see you watching her or she may abandon the hole...it can push her towards eggbinding.
She may dig several test holes, but should settle on one and dig it until she is satisfied with it. It may take more than one day to dig it. When she is happy with the hole, she should turn around butt down and lay the eggs...likely in the evening. Once she is done, she should fill the hole in, tamp it down and return to the branches. She should be hungry and thirsty after all the work.
If she does not do the above or digs the hole, seems to be laying the eggs, fills the hole in but has not laid the eggs, sits low in the cage, seems lethargic, etc. then she is likely heading towards eggbinding.