Maybe. Does she show any other sign's of broodiness? Like puffing out her feathers, walking around making low clucking noises, not allowing rooster to mate? If you take her off does she go right back in? My Buff Orp puff's herself up size of a basketball, holds her wings out, and goes in circles clucking and just generally cranky with the other hens. Then she's right back on the nest.
If she sleeps in the nest box tonight, and goes back in when you take her off, she probably is starting. Better to break her now if you don't want her to go full broody. It's lots easier when they first start. Once they go into the hormonal broody trance and puff up and get irritable it's harder.
She does growl at other hens but not at me. She does notice when I take the eggs and freaks out. When I took her out, she stayed out, ate, drank, and took a LONG dustbath and went back in. At night she slept on the roost but today she is there again. Same is happening with my Japanese but exactly the oppisite, she's in there at night and not during the day. Whats wrong with them!