It's ok, don't freak out about egg-laying. It's nerve-wrecking for us the first time but they've been doing this a really long time, so as long as you give them what they need to lay properly they know what to do.
Once you put the laying bin in her cage (or put her in a large laying bin outside of the cage) she will need total privacy. So either leave the room she is in alone or drape a sheet over the cage so she doesn't see any activity. If she doesn't feel safe and private she may retain the eggs, and that's not a good scenario. She could take up to 2-3 days to dig a tunnel she likes and lay her eggs, and she may even sleep in her tunnel at nights until she's done.