I have my first ever broody mama duck

we couldnt find her the other day and thought maybe a predator got her. But with a little searching, we found her behind the pool. We had it blocked off, but she got past the wood and brick barrier and dragged straw all the way back there. She started sitting yesterday and wouldnt come off the nest. Eeeeeeeeeeep!
So what do i do with a broody duck? I know what not to do, and thats bother her. She will be left completely alone. But do i need to provide food for her back there? Its a pretty tight fit. Will she get off and eat at least once a day?