One naughty chicken who refuses to lay in nest box

So my girls are big girls now!
Buffy

Biddy & Peeps

Nefertiti

Peeps
The pics were taken back in December and the combs have filled out and are cherry red now. All but the Buff Brahma are laying. Yay! There is nothing like fresh eggs.
My Polish was the fist one to lay and lays about 5 eggs per week! I could set a clock to her laying. She is living up to her queenly name.
The Australorp's are starting to get it down. However, Mrs. Biddy refuses to lay in the nest box(the other 2 are laying in the nest box). For a awhile she would lay right outside the next box but now she lays in random places in the run. One day it was right in the middle of the run. I think she doesn't want to miss a thing and needs to be near the others. So much for chickens liking dark quiet places to lay. I have curtains on the boxes and had golf balls in there for a while but the other two just keep kicking them out so I took them out. Any suggestions to get Mrs. Biddy to lay in the nest box?
Also, what are your experience with Brahma's laying? She just started egg squatting if I corner her. Her combs is pretty red. She doesn't come up to me and egg squat like the the others though.