Broody hen breaking eggs

[Northern nurse]

So just wondering if this is common. I have a Wyandotte that went broody so I decided to let her some sit on some fertile eggs (ordered some eggs off ebay) and put 6 eggs under her. A few days later I notice there are only 5 eggs there with NO evidence of the missing egg. She is in a sectioned off coop so none of the other hens can get to her. A few days later, another egg goes missing! This time, I find part of the shell under her. I decide to pull the other 4 eggs and put them in an incubator, I gave her 3 infertile eggs to sit on while the incubator does it's job. My plan is to put the babies under her once they hatch. We are at day 16 so just a few more days to go. Today, I discover her had broken one of the infertile eggs she was sitting on! Not sure what is going on, I had one other hen sit on some eggs a few weeks ago and although I did have one egg go missing, the rest were fine. I don't know if she is too rough when she moves them around or if she is too heavy or what. This is her first time sitting on eggs. Do you think there is a good chance of her taking on the chicks that are cooking in the incubator? Is it common for a hen to break/eat her eggs when broody?

 

[sourland]

Some hens are just clumsy and may break eggs inadvertently - does she have a well formed nest of a good material? Grass hay has always worked well for me. She should accept the chicks readily - hopefully she will be more careful with them.

 

[Northern nurse]

Some hens are just clumsy and may break eggs inadvertently - does she have a well formed nest of a good material?  Grass hay has always worked well for me.  She should accept the chicks readily - hopefully she will be more careful with them.

She does have a hay nest but she moves the eggs around quite frequently and I noticed this morning she had shuffled the hay around enough that the eggs were actually on the wooden floor. Sigh... Hopefully I will get babies from the incubator and she will accept them (and be careful with them!).