I’ve had my light off this week in the house, mine in the house are 4 weeks old, I keep my AC at 78 but in my office it gets warmer because I work in there and my computer is a graphics beast lol also it’s a small room and there is another brooder with a lamp on, plus an incubator lol!
But I think I would have it off anyway, they don’t seem cold at all, but then they do have friends. They are almost fully feathered. I moved some outside last week. It’s in the 90s.
I def would turn it off at 6 weeks even though she’s alone but you know what? You could switch the bulb out - why not just give her a normal light so she gets plenty during the day time? And then flip it off at night so she’s on a schedule?
We give ours a normal light sometimes if they are in the house extra long. But I just replaced the bulbs in my office it’s very bright now.