I think Natalie is definitely to do with Chelsea because her business is to supply girls (or in the past, herself) to rich people in the area.
A couple of things I picked out from press releases
Charlie - "Charlie is a stripper who attended a strict Catholic school, and also
a serial cheat who has been unfaithful in the majority of her past relationships."
Natalie - "Natalie claims to have supplied prostitutes to wealthy clients, operating the Black Beauties escort agency and working under the name "Miss Whiplash" or "Mistress Pain".
She lists her clients as "high-flying Tory politicians, City bankers, judges and A-listers"." - links to Chelsea tbh