best way to add new breed with broody?

[wild chick]

I have a broody hen & am thinking of adding some different breeds to the flock. I could order fertile eggs or live chicks - Is there a preferred way? If she's positively broody by tomorrow, how soon does she need fertile eggs so she won't spend overtime waiting for them to hatch. If I can pre-order day-old chicks, would I do it for the closest date 3 weeks from today? What are the chances of her rejecting live chicks when slipping them under her in the middle of the night? Thanks!
Also, on eggs, best reliable recommendations?

 

[azygous]

One thing you can predict is unpredictable behavior from a broody. There's no way of knowing her reaction to day-old chicks until you try it.

You do increase your chances of her being amenable to the adoption by waiting until she's been broody between one and two weeks, the closer to two weeks being more optimal.

On the other hand, placing fertile eggs under her is less risky. You may do so anytime after she's been on the nest for several days. Chances are good she will begin the 21 day countdown when you present her with the eggs, but you need to consider that the longer you wait, it means that much longer she will be going with minimal nutrition and it will take its toll on her body. So sooner is better in the case of incubating eggs.