Yes, if she's seriously broody, she'll sit tight anywhere. Mine have all gone broody in the hen house and I've always separated them off before putting serious eggs under them (my own chicken eggs are not 'serious' because the cockerel's of dodgy heritage). I tend to move them onto fake eggs first and then once they're settled on those, I put the proper eggs under. Often easiest to move them at night (or at least evening) because they'll just got straight to sleep. Mind you, I have Orps which are just big and dopey. Maybe other hens are a bit more feisty when you move them,
H