Who is Juanita del Pablo from The Loved One and what is their importance?

Juanita del Pablo is the actress for whom Sir Francis tries to create a new biography after the executives at Megalopolitan Pictures decide that her dark, Spanish style must be replaced for a more family-friendly, Celtic personality. She does not appear in the story, but her situation provides the opportunity for Evelyn Waugh to satirize the Hollywood star-making system.