This is a simple birthday card sent in 1916 in Doncaster. The sender is unknown. The angle of the stamp suggests at a deeper relationship than just friendship.
A birthday card for Agnes Ribbans in Acle, Norfolk in 1910. It was sent care off the Police Station not because of any wrongdoing, but because the Superintendent was her uncle.
This birthday postcard was sent in 1935 from a husband to his wife. They lived in a small Norfolk village so you wonder why he put a stamp on it and posted it. Perhaps she liked receiving post.