The author of the “Harry Potter” series, JK Rowling, a vocal critic of transgender rights activism, is calling out the actor who played her Hermione character on the big screen, Emma Watson, as “ignorant” and opportunistic following a recent interview in which Ms. Watson expressed her ongoing affection for the author despite years of criticism about her.

Ms. Watson and her former co-stars, Daniel Radcliffe and Rupert Grint, have emerged over the past five years as vocal advocates for trans rights. In doing so, they have publicly condemned Ms. Rowling’s position as transphobic. However, in a recent interview on the podcast “On Purpose” with Jay Shetty, the actor said that she still “treasured” Ms. Rowling. 

“I really don’t believe that by having had that experience and holding the love and support and views that I have mean that I can’t and don’t treasure Jo and the person that I, that I had personal experiences with,” Ms. Watson said during the interview, referring to Ms. Rowling’s first name, Joanne. “I will never believe that one negates the other, and that my experience of that person, I don’t get to keep and cherish.

“I hope people who don’t agree with my opinion will love me, and I hope I can keep loving people who I don’t necessarily share the same opinion with.”

Ms. Rowling, breaking what she said was a self-imposed refrain from speaking about the star, who was 11 years old when she and Ms. Rowling first collaborated, called Ms. Watson’s remarks disingenuous.

“Like other people who’ve never experienced adult life uncushioned by wealth and fame, Emma has so little experience of real life she’s ignorant of how ignorant she is,” wrote the author, who lived in government-supported housing with her infant daughter when she penned the initial chapters of “Harry Potter and the Philosopher’s Stone,” in a lengthy post on X. 

“Her ‘public bathroom’ is single occupancy and comes with a security man standing guard outside the door. Has she had to strip off in a newly mixed-sex changing room at a council-run swimming pool? Is she ever likely to need a state-run rape crisis centre that refuses to guarantee an all-female service? To find herself sharing a prison cell with a male rapist who’s identified into the women’s prison?”

Ms. Rowling addressed past calls for her assassination over her viewpoints — threats that re-emerged in the wake of Charlie Kirk’s assassination by a suspect who was reportedly in a romantic relationship with a transitioning man. 

“The greatest irony here is that, had Emma not decided in her most recent interview to declare that she loves and treasures me — a change of tack I suspect she’s adopted because she’s noticed full-throated condemnation of me is no longer quite as fashionable as it was — I might never have been this honest,” she said.

“Adults can’t expect to cosy up to an activist movement that regularly calls for a friend’s assassination, then assert their right to the former friend’s love, as though the friend was in fact their mother,” Ms. Rowling said.