“I am told that people have been twittering on my behalf, so I thought a brief visit was in order just to prevent any more confusion!”

This was the inaugural tweet of J.K. Rowling, author of the acclaimed Harry Potter book series. Since then (September 2009), Rowling has cultivated a reputation as an author ready and willing to personally respond to her fans’ questions. In recent years, she has fielded much online criticism for expanding the Harry Potter world beyond the initial series, in somewhat tone-deaf attempts to make her characters’ world more diverse.

Rowling has two strategies for making Harry Potter more multicultural: Twitter interactions with curious fans, who often want to know if their identities are present in Harry Potter, and pseudo-encyclopedic entries about character backstory and world-building published on Pottermore, the interactive Harry Potter fan website. In Rowling’s tweets, her assurance of fans that they are, in fact, represented in her world, feel more like surface-level tokenism than meaningful reflections on her work. On Pottermore, Rowling’s essays about magical communities outside of the U.K. reveal her inexpert knowledge of other cultures and histories.

In early March, Rowling published on Pottermore a four-part “History of Magic in North America,” which provided a stereotypical portrayal of Native American cultures. Several Native American groups have spoken out, saying Rowling’s depiction of indigenous people as practitioners of “animal and plant magic” plays into historical representations of Native Americans as noble savages. These groups, as well as individual fans, also object to Rowling’s blanket use of the term “Native American community.” If she can bother to differentiate between the cultures of different houses at Hogwarts (Britain’s top wizarding school and the original books’ main setting), surely, they say, she can differentiate between tribes.

One of the most inflammatory aspects of “History of Magic in North America” is Rowling’s description of “skin-walkers,” people with the ability to transform into or disguise themselves as animals. This is a concept lifted from Navajo religious beliefs, which Rowling attributed to all Native Americans as an example of nature magic. On March 8, Rowling responded to a fan’s request for an explanation about skin-walkers with the following tweet: “In my wizarding world, there were no skin-walkers. The legend was created by No-Majes [non-magical people] to demonise wizards.” This statement upset members of the Navajo Nation because skin-walkers, considered evil and dangerous creatures, are an important aspect of their religion. Rowling’s attribution of skin-walkers to her fictional world plays into a long history of calling Native American beliefs magical, making it easy to dismiss their cultural importance. Adrienne Keene, a post-doctoral fellow in Native American Studies at Brown University and a member of the Cherokee Nation, describes Rowling’s blunder in a blog post: “If Indigenous spirituality becomes conflated with fantasy ‘magic’—how can we expect lawmakers and the public to be allies in the protection of these [sacred Native American] spaces?”

Skin-walkers in “History of Magic in North America” is only Rowling’s most recent misstep in expanding diversity in Harry Potter. In December 2014, Rowling answered a tweet asking about Jewish wizards at Hogwarts with the following: “Anthony Goldstein, Ravenclaw, Jewish wizard.” Although Rowling probably meant to use Goldstein as an example of Jewish wizards at Hogwarts, rather than singling him out as the only one, her reply comes across as flippant. Fans were also quick to point out that Goldstein is a very minor character in Harry Potter, which barely evokes his personality, much less his Judaism. (And how many Jewish couples would name their child after a Catholic saint?) Rowling was similarly called out for her revelation in late 2007 of Albus Dumbledore’s homosexuality, since the original books don’t mention of this aspect of his character. Put simply, Rowling’s after-the-fact pronouncements about her characters’ diverse identities are too little too late. They feel inadequate and even opportunistic.

Rowling has not yet responded to recent complaints made about skin-walkers and “History of Magic in North America.” Her silence is unusual; perhaps she is taking her time to come up with the right response. In the meantime, she should remember how the original Harry Potter books gained the recognition they did. Rowling earned her fans’ respect for her nuanced usage of European mythology in her writing. Much of the magic in Harry Potter comes from her detailed knowledge of British culture and history. But her sloppy treatment of Native American cultures is clearly not up to par with her past work. Ultimately, if Rowling plans to continue expanding the world of Harry Potter, she should make sure the quality of her world-building matches that of the original series.