Petra Danford is a night witch originating from Britannia.
Background
After the Dunkirk operation, a night combat unit was formed in a hurry to defend London, and Petra was selected. However, there was no noticeable activity or night battle.
Trivia
She is based on Peter Dunford, a pilot using a night battle specification Spitfire.
References
Strike Witches II A complete record of 501st Joint Fighter Wing 2.