moving eggs to a broody

[only one lay]

Hi all,
I have silkie's and vorwerk's that are hatching machines. They just sit and sit and sit. My reg flock choose not to sit long enough to hatch, or they just choose not to. Whats the best plan or action,timeing to get eggs under those hens. Will they just accept the bigger eggs, is their a good time to add them,? Thanks Al

 

[Zaxby's2]

Quietly put them under her at night, that way she isn't as disturbed and will except them better.