SHE'S BROODY!!!!! (formally A problem with my muscovy's nest)

My muscovy has been laying for about 2.5 weeks now.  I built her a little shelter and she set up shop there.  One problem I have been having since she is not setting yet is some of my chickens have dediced that it is a great place to lay their eggs.  Since my muscovy isn't setting, I just check the nest and remove any chicken eggs.  No big deal, I thought.

This morning, there were some feathers in the nest so I am thinking that she may have started plucking and may set soon.  Later on, I was outside building a holding pen for some meat chicks and started wondering where my girl was because my drake kept coming over to see what I was doing.  I went to check if she was in the nest and she was but my brown leghorn was standing there pecking her in the head.   I removed the hen and closed up the duck run.  My poor scovy had a little blood on the top of her head and behind on e of her eyes.  She is not too keen on me touching her so I kept an eye on her and she looks okay.  She stayed on the nest for a few hours today and when I noticed her pacing I let her out of the run.

I have had problems with this leghorn hen before, she used to pick on the muscovy when they were younger and they are scared of her. 

Suggestions for what I should do to resolve this situation?  I don't want to leave the ducks in their run all the time, maybe once she starts to set but not yet. 

Thanks everyone.  I'm thinking I will try to pen up the leghorn.  I have some of the first scovy eggs that I can give her to sit on in the chicken coop.  I think she wants to set.  She has previously started a hidden nest (last year). 

If it continues after that then I think she'll just go to the freezer.  I have 3 week old Rouens that I don't want to be paranoid of the chickens.  The other 4 chickens are fine although the ducks are scared of them too.

It is kind of funny seeing a drake that is about 4X the size of a chicken jump (literally) when he realizes they walked up behind him.  I did scold him for not being a good drake and protecting his girl from the $!#@#% leghorn.

Oh, Miss Lydia, I don't know how long your hen has been laying in the chicken coop but you may want to try setting up a nest for her in her area.  My girl disappeared one morning after she had been laying for about 1 week.  I found her in the hen's nestbox.  The next day I didn't let the ducks out until she laid her egg and have had no problems since.  I "tested" her for her nesting ability a few days ago by putting extra hay near her nest.  The next day she had added it all to her little nest.   I can't wait for little scovy babies. 

UPDATE

Well, my girl is going broody.  I have not had to worry about the leghorn since my muscovy is only getting off of her nest only 2-3 times a day.  When I'm home I let her out in the morning then close the door to the run when she goes back in.  In the afternoon, when I see her pacing, I let her out again.  She does enjoy hunting flies.

She is still laying so she has 11 eggs under her now.  She is starting to pluck more.  I have been dating the eggs so I know which are older. 

I know that they can lay a ton of eggs but should I remove any older ones and leave her with a set number?

I couldn't resist adding this.

Anybody have an opinion on the egg question?  :)