It’s always worth a try! When using a broody things can go wrong regardless off how experienced they are, sometimes the hens that have sat multiple time’s still get off and desert their nest.
The main thing I find with new broodies is that they do go back to the nest but they either don’t cover all the eggs properly or they get out to go and eat for too long.
If she’s a USA bantam size then she should be able to sit 10 - 12 nicely. You may feel some poking out from the side of her but you’d be surprised that they still tend to hatch because they all get moved around anyways.
The much smaller British bantams can usually sit around 6 - 8 quite nicely
Thank you both! So I guess I'll place as many eggs as I get today under her. I'm only expecting one more. Apparently we ate most of our eggs, so we have less than I thought, but I found three to put under her (hopefully four soon). Guess we'll see how it goes!
)
I really need silkie chicks! Like right now! 
