I suspect she was always easily led by whispers of money making which is why she retained a team in the US after marrying a Prince and was then seduced back hoping to use the fame to get very rich.
In the book 'Revenge',Tom Bower talks about this. IIRC MM initially let Sunshine Sachs go when she joined Harry in London, but she then re-hired them when the UK press started writing mean and horrid stories about her. Their job and that of her US pals was, of course, to provide positive stories about how wonderful, sweet, kind and naturally charitable she is.
I think Bower also said that her sleb chums were urging her to quit the RF from quite early on, saying how if she and Harry moved to the US they could easily make loadsa money just for who they are i.e. ready-made A-listers, who would be loved and feted by all. And initially that happened - the US coverage was massively positive, people believed everything they said about the mean, cold, racist old RF, they got huge deals with Netflix, Spotify and Random House for basically doing nothing - just for being who they are.
But it's like any other son or daughter of someone famous - your name will get you through the door and give you opportunities that others can only dream of - but you've then got to prove that you've got some talent, something unique, that you can generate revenue - and that's where 'call me Harry' and The Duchess of Sussex fall down, because all they have is their name. They're empty vessels.