New chicks with hen up high...

[Peetie]

I am a newbie with chicks and my little Lucy Banny just laid 4 eggs about 21 days ago. ;-) I have been checking every day many times a day for new babies...so today....I saw and heard a new baby chick! My problem is that she laid and sat on the eggs in a nesting box that we attached to the wall. I sat a partial crate filled with cedar shaving underneath just in case. I know many people are laughing but I am worried about how the chicks will eat (I have new food for them and a chick watering device) but most of all, how will they get out from a 4 foot high nesting box.... Please, any help would be appreciated. I am very nervous and proud of my new momma and her (1 chick that I can see so far). Oh and she seems to be a good Momma...won't let me near...If it is advisable, I can certainly pull Lucy off the nest but I don't want to disturb her if it is not advisable.
Thank you!
Peetie