Anne Hathaway's friend from the OG PD1 (Heather Matarazzo - had to look it up) either also discovered that she was part of a royal lineage/married into royalty & now has a daughter who's of the same age as AH 21 years ago. She approaches AH to become her teacher (she's also her godmother). AH agrees but soon is forced to realise that the world has changed a lot & she needs to adjust her ways aka learning curve for both teacher & pupil. Julie Andrews could make a cameo appearance to help her out.
There, I'll have my name in the credits please (along with the cheque). That movie should get a B- in reviews & make 50m at global BO (20m US) - recouping costs - and hopefully killing any thoughts of a PD4 for at least a decade.