My Buff started laying and just under 21 weeks. Hens will often get a bit antisocial when they are about to start. I think she's ready. If she's 7 months, she's already late to the game.
You say she's 5.5mo old? Has she started laying yet? My BO started that type of behavior just before she started laying. She'd dig out a rut and lay around in it for hours. If she hasn't started laying yet, I'd say she's about to.