@feha I try to keep consistent so I do tend to reference myself sometimes but it's hard to reference something that's not available (for free).
I just doubted she would have changed shoes. Firstly, she was trapped in the mall but even when she left she was at a stationmaster on the radio calling for help but was injured. She is seen later zombiefied and in uniform. I feel it unlikely she'd just change her shoes only, and unlikely went home.
The other faction is the garrison which is written in the notes that the girl with the radio wrote before she died (in the Volume 6 extras, not an April fools):