Her behaviors do indicate she may be going broody. I've only had one pullet go broody at 6 months, but several who have done so at 7-8 months. If she is still laying she's not ready to incubate a clutch yet, but within a few days her hormones will tell her "it's time" and you will find her glued to eggs in a nest. I agree with @Chicks n stuff that winter isn't the best time for a broody to hatch and raise chicks, but if you live in a warmer climate it should be OK.