Does my broody turn her eggs evenly?

[Johnchickens2]

I read that a hen turns her eggs 4 times an hour but I have to say I don't always see that my hen is turning her eggs. And I don't understand how she can turn each egg if they look the same - she doesn't mark them like we do...
Im asking because today when candling I saw that there are veins only on one side of the egg.....

 

[Sussex19]

She knows what she's doing : )
I hardly ever see my broody hens turning their eggs, (and they usually do it with their wings and bodies, not beaks) but they have very good hatches.
Also, most of my eggs look like the veins are only on one side early on, I don't know if thats just how they develop, or if it is something the hen is doing, but again they all hatch fine.