The “Bridget Jones” franchise is long beloved by fans, due in extremely large part to Renée Zellweger’s portrayal of the title character. So, yes, the actress was a resource director Michael Morris turned to a lot while making the fourth film — and there was one particular insight from the Oscar winner that he says unlocked the whole thing.

The actress, 55, kept it classy on Wednesday, Feb. 12, while attending the New York City premiere of Bridget Jones: Mad About the Boy. Zellweger’s costars Leo Woodall and Chiwetel Ejiofor also attended the event at Jazz at Lincoln Center.

Zellweger spoke exclusively to PEOPLE at the N.Y.C. premiere of the franchise's fourth film on Wednesday, Feb. 12 Renée Zellweger is waving goodbye to her iconic character, Bridget Jones. The actress,