is my broody eating enough
Broodies do not want to be seen going to/from the nest - it is instinct for them to make these trips as secretively as possible so as not to draw predators (you are seen as a predator in this situation) back to the nest and reveal it's location. She is getting up when she feels safest to do so, which is when no one is around watching her. When you remove her from the nest that is distressing and her instinct is to get back onto the nest as quickly as possible.
In cooler weather I’ve seen a hen stay off the nest for fifteen minutes, rushing everywhere and not being real nice to any chicken that got in her way. That’s the behavior I’m more used to with a broody. Often I never see a broody off the nest. But since she is not pooping in the nest, she is leaving. I just don’t see her.
Different people do this differently, but I leave my broodies alone until she brings the chicks off the nest. I do check under them every day after all eggs are laid to remove any I haven’t marked as belonging, but other than that I try to be very hands-off.