Dirty nest question

My Snowy Mallard girl has started setting. She resides in the coop with my chickens and her nest bucket is on the floor next to the ones for the chickens, which are slightly elevated. Their nests stay relatively clean with normal dust and feathers but hers seems to collect junk. Everything from dirt and feathers to poop. I fully cleaned the coop this past Saturday and refreshed all the material in the buckets and set her eggs in there in hopes she would start setting, which she did. I've noticed her nest getting dirtier and dirtier since I cleaned and I've seen her goofy little butt push stuff in there with her bill. Like she's trying to make it messier. Is this normal? I've had broody chickens and have cleaned nests while they're brooding with no issues but this is my first time with a duck and I want to give her the best chance of hatching off some babies. I want to clean her bucket but I don't want to bother her and maybe make her quit. Are ducks more sensitive to these kinds of changes or am I worrying too much about it?

Also, when can I first candle a duck egg? Same as chicken?

Well she might be trying to get more feathers in the nest but relations very a ducks nest is the cleanest thing that they do. So idk just watch her and if it gets to dirty just clean it

If this is her first go around, she may do some non-standard things.

When my ducks make nests, they are generally pretty clean, but sometimes a little poo sneaks in around the edges. Mine do line their nests with feathers.

I also don't give them a nest bucket, they make their nests in corners...

This is her first time. She chose the bucket. I cleaned it out she went back for about half a day and quit. Oh well, maybe next year.