Just adding that sometimes it's best to limit your participation to being slightly helpful in securing the shelter. Adding food, etc. might attract other animals or increase territorial behavior. Low key interaction and extreme discretion is probably safest.

Ledonna, fingers crossed!

Isabel, I did feel like I was getting too emotionally invested in this duck. i haven't put out food (not sure what they eat!), just some water.

The nest is empty again. My husband thinks she was in the middle of laying last time and that's why she came back. Again, there were no shells or shell pieces around. I think it may have been a raccoon. They would be able to carry eggs away whole. I know they can be active during the day, as I saw one mid day when we were in Texas last week.

I hope she's okay, though.