Why wont my chicken sit on her eggs?

There could be several reasons your chicken isn't sitting on her eggs. She may not be broody, which means she isn't in the instinctual state to incubate eggs; some breeds are less prone to this behavior. Additionally, environmental factors like stress, temperature, or insufficient nesting space can deter her from sitting. Lastly, if the eggs are not fertilized, she may not feel the need to brood them.