Make sure the amount of sand is around 12" deep as she may want to dig to the bottom and you don't want her to dig further than necessary.
I wouldn't keep her in the bucket for more than a day if she is not digging. If she is in there all day and doesn't dig, I would place her back in her cage for a day to dehydrate and eat if she is still eating, and then try again for another day till she starts to dig and lay.