Around 5-6 months old, she’ll start showing some beautiful colors/patterns and be restless. This is her receptive phase when she is looking for a man. This is the time you’ll need to get her lay bin ready and is just easiest to make it a permanent part of her enclosure rather than guess when she’ll be needing it. I gave my ladies a large bin around 12-14” filled to around 8-9” of moist play sand. You could get a little smaller bin than that if you like...like around 9-10” and could probably get away with 6-7” deep of play sand.