When you got her a few days ago, she was already laying and there were eggs in her system. The stress of moving will usually cause hens to stop laying for a week or two until they settle in, but the eggs in their system will come out first, so it's not unusual for a hen to lay eggs for a couple of days at her new home and then stop. If this hen is alone, with no other flock members to keep her company, she may well be staying in the nest box because she feels that that is the safest place. Flattening down when you approach may just be her cowering in fear. Of course she could be going broody but I think the circumstances are more likely to be a contributory factor to her spending time in the nest box than her hormones. Hens don't like to be on their own. She's in a strange new place with no flock mates.... my bet is that she is hiding rather than broody.
new hen broody?? - Page 2
she is starting to lose some of bottom feathers on her belly only broody hens do that right? she is on 3 eggs now and wont eat today she only ate a little and drank some water with vitamins and electrolytes she is pooping lots and smells bad its very big like a broody but that could be something else all the eggs are her non from others I got some eggs from her from the owner that I got her from (he puts names or marking from the egg that hen lays to know whos egg is it) he gave me 2 of hers I want some other breeds to I will get 3 from my friend today