A disgruntled chicken may hop back into the egg box once you put her down, so if she does, simply remove her from the nest and carry her around again.
I’ve found that even the most stubborn broodies (like my Wyandotte this summer, who actually forced her way into the coop when we tried to block it) will get off the nest if there are new flock members around.
The theory here is that you’re helping cool down her chest and her vent, thereby lowering her broody body temperature.
For good measure after doing Methods #1 or #2 above, I also lock my broody out of the coop; I do this when I know my other chickens have already laid an egg for the day.
A chicken jail can be a wire dog kennel, a rabbit hutch, or an enclosed pen (which some flock owners keep as “hospital pens” for quarantining sick hens or isolation pens for introducing new flock members).