I’m at a disadvantage here though. My broody took 5 two day old chicks at 2 in the afternoon. I’d swear she’d incubate my work boots and adopt a Great Dane if it meant she could be a momma hen.
The chicken may lay waste to your best laid plans.
You could try to time it so they appear and hatch within a small window. Say getting new chicks and placing under her on Thursday afternoon/evening and hoping her setting will be enough to hatch her own eggs before moving off.