If she is broody, and you do not want her to hatch any fertle eggs you could come up with, and you do not desire or have room for more chickens, you should break her brood. You need to do this for her health sake.
Brooding takes a total on health due to inactivity and dietary restrictions and lack of sunlight. In a natural circumstances a hen would only be in hard brood for 3 weeks then chicks arrive and she returns to normalicy with her chicks.
In circumstances with no rooster, a hen could remain in hard brood indeffinatly trying hard to hatch infertile eggs, golf balls, rocks etc intil she finally gives up, or dies (rarely).
In any case the longer she continues to set she becomes less healthy and open to lice and mite infestation among other things
Some breeds have a high brooding instinct and your girl may be one of those. In my flock I have girls that never go broody, older girls that have only gone broody once or twice, and regular broodies that do this every year, sometimes twice a year. Some go broody in the dead of winter even!
Their are good articles here in different methods of breaking her broodyness.
In short get her outside, in the day light.
Good luck!