Odd behavior in Bobwhite quail

We're the ones with the quail who came to live with our chickens.
She's been roosting with (and sometimes on) the chickens since
December. She's always gotten along really well with the chickens,
and stays with them in the yard during the day.

About 2 weeks ago, when I let them out in the morning, the quail
started acting really wild...she began chasing chickens at top speed
around the yard, and the chickens yelled and ran as fast as they
could with this tiny quail chasing them. The quail seemed to only
target 2 chickens for chasing, and she jumped and pecked at them
when they came into her eating area. Then she cornered them in
the chicken house, and they turned on her, pecking her repeatedly
until she squeaked and ran away. For awhile after that, she stood
on one leg with her eyes half closed and I was concerned that she
was seriously injured. However, she recovered with no difficulty.

She was back to her normal behavior for a couple of weeks until last
night, when she didn't come in to roost with the chickens for the first
time since December. I was concerned that something happened to
her, but she showed up in the yard this morning to eat. However, as
I was throwing scratch out, she gave an odd call I've never heard
before, bent her head down to the ground and fluffed her feathers up
and then stretched herself up as tall as she could in front of a chicken,
challenging her. The chicken backed off, and she was back to normal.

My questions: 1. Without a male bobwhite around, would she still be having
maternal/nesting instincts and acting territorial with the chickens?
2. Any ideas for why she might want to stay out at night
now? Would she be wanting to build a nest without a mate??

Thanks so much for any input. Obviously, I'm very green where quail are
concerned, and only know what this one female has taught me.

Fencerow