Vintage Worthington Lady Diana Pastel Golf Ball

This is a new, unused, set of three Lady Diana Worthington paster golf balls. The original cellophane was torn open one side. They belonged to our aunt, an avid golfer, but we do not know the year made or country of origin. Similar balls for sale say Burke-Worthington but our package does not state "Burke".
Not sure the meaning of "Lady Diana" either, however Googling "Lady Diana Worthington" retrieves links to history of Lady (Mary) Diana Worthington" a person of some English nobility. The balls look to old to commerate Lady Diana Spencer.