Ordered some day olds for my broody Momma

[ButchGood]

I got a big ole' Buff Orp that went broody, Im in texas and the temps stay pretty warm so I let her go with 7 eggs. Ive been candling and Im not to impressed in what Im seeing. I'm hoping that at least one or two will hatch, but Im not seeing real good sign. eggs are due to hatch the 16th. I have run out off chicken in the freezer so I ordered 12 Red Rangers. They're coming in the 26th. Im hoping I can sneak these birds under her at night. If the eggs are all duds I'll pull the eggs and replace them with the chicks. She'll just have to sit 10 more days. If a couple hatch, I'll have to slip them in with a couple 10 day old chicks.
Anyone here have experience doing this? If so. your remarks are welcomed.

 

[AlienChick]

You can try putting some chicks underneath her.
In the morning you'll know if she'll raise them.
If the chick was kicked out of the nest during the night, it'll probably be dead by morning.
Sometimes the mom will squash the chick.
Sometimes the mom will peck it to death.
I've had all of the above happen on the occasions I tried to sneak in a chick under a broody (the times it didn't work).
It always works best when the broody has just hatched a chick.
Even though I haven't had very good luck, there are people who post here with great results.
It can't hurt to give it a try!