Womens Auxillary Air Force Insignia

[blagle]

Hello, I'm new to the forum and was hoping somebody could help me interpret the badge on my grandmothers uniform. She was born in the UK and joined the WAAF but I'm puzzled that she has a USA badge on her shoulder. She was in Scotland at the time this photo was taken with my Grandad (her wedding day I think). Grateful for advice why a UK citizen would have USA insignia.