A bit of a dilemma

I have a shed that I use for my work and a few weeks ago, I noticed a birds nest on the rafters at a point where several narrow pieces of wood cross. The wood is being stored overhead and has been there a long time.

This particular bird, or another one, had a nest in the exact same location, last year but the eggs got raided. I suspect the culprit was a red squirrel who also had had a nest on the other side of the barn.

While the parents were nesting, we got along just fine. I would wait outside the door and give a holla to let them know I needed to go inside, and she would promptly fly out the door. I would go inside to retrieve my wood and do my cutting and planing or whatever I had to do for my customer and then I would leave, whereupon, mother bird would return to her eggs.

I have noticed no sight of mom for the last few days and I am wondering what happened to her. Today I went inside to do some work and I could hear the sound of peeps so I looked quickly overhead and saw a bunch of little birdies who looked hungry. I asked my friend what I should do and she said nothing. mom knows they are there and she will be back. She's probably looking for food.

Now my question. Will it terribly upset them if I go in there and make some noise for about an hour or so? My friend said don't go in there at all until they have left their nest but I'm thinking....I don't want to go out of business. I did not do any work today but if I don't try to get something done tomorrow, I'll get behind.

Does anyone have any suggestions on how to handle this?