She has received a lot of backlash for her Tweet.

Yesterday, J.K. Rowling tweeted her support of Maya Forstater, who lost her job in March at think tank Center for Global Development after sharing controversial opinions on social media. Forstater’s contract had not been renewed after she posted a series of anti-transgender tweets. Maya Forstater’s tweets opposed the British government’s plans to reform the Gender Recognition Act and allow people to self-declare their gender on their birth certificates. She argued that “men cannot change into women”. J.K. Rowling’s tweet came yesterday, after an employment tribunal dismissed Forstater’s case, in which she claimed that her opinion should be protected under the 2010 Equality Act. The author of the famous Harry Potter books tweeted: “Dress however you please. Call yourself whatever you like. Sleep with any consenting adult who’ll have you. Live your best life in peace and security. But force women out of their jobs for stating that sex is real?” #IStandWithMaya #ThisIsNotADrill” https://twitter.com/jk_rowling/status/1207646162813100033 She has since received a lot of backlash and criticism on Twitter, with people calling her transphobic and referring to her as a TERF (trans-exclusionary radical feminist – a term for someone who calls themselves a feminist but rejects the rights of transgender women). Many people referenced the Harry Potter series, saying that the books had always been a safe and accepting place for them to escape to and that her comments came as a huge disappointment. https://twitter.com/shahmiruk/status/1207666369543786497 https://twitter.com/LouisatheLast/status/1207667162615300102 Mara Wilson, best known for her role in Matilda, tweeted in response: “What, exactly, is to be gained by using your platform to be cruel and exclusionary to one of the world’s most vulnerable populations?” https://twitter.com/MaraWilson/status/1207768242434920450 However, others on Twitter have voiced their support for both J.K. Rowling and for Maya Forstater and have joined in with Rowling's use of the hashtag #IStandWithMaya. J.K. Rowling has yet to say anything else publicly on the topic. During the tribunal, Maya Forstater argued that “sex is a biological fact, and is immutable. There are two sexes, male and female. Men and boys are male. Women and girls are female. It is impossible to change sex. These were until very recently understood as basic facts of life by almost everyone.” However, Judge James Tayler, who was presiding over Maya Forstater’s tribunal, said that her views did “not have the protected characteristic of philosophical belief”. In his final judgement, he called out her insistence in referring to people by the sex she believes them to be, regardless of how that person identifies. “[Forstater] is absolutist in her view of sex and it is a core component of her belief that she will refer to a person by the sex she considered appropriate even if it violates their dignity and/or creates an intimidating, hostile, degrading, humiliating, or offensive environment. The approach is not worthy of respect in a democratic society.”