The 28-year-old Irish singers tweeted the Harry Potter author as her row about gender was reignited by the revelation her latest detective novel Troubled Blood features a cross-dressing serial killer.
Jedward tweeted: “#TransRightsAreHumanRights Understanding is the first step to acceptance.
“@jk_rowling and only with acceptance can there be recovery It matters not what someone is born, but what they grow to be! Every human life is worth the same, and worth saving!”
They also tweeted: “We couldn’t be more proud of our fans! Over the years seeing the growth and development finding who they are and becoming their true authentic selves! We LOVE You #TransRightsAreHumanRights”
Rowling, 55, was accused of transphobia after a series of posts on Twitter in June, responding to a story with a headline which read: “Opinion: Creating a more equal post-COVID-19 world for people who menstruate.”
She tweeted: “‘People who menstruate’. I’m sure there used to be a word for those people. Someone help me out. Wumben? Wimpund? Woomud?”
The comments caused a widespread backlash, with Rowling accused of being for being “transphobic”.
She defended her views, tweeting: “I respect every trans person’s right to live any way that feels authentic and comfortable to them. I’d march with you if you were discriminated against on the basis of being trans. At the same time, my life has been shaped by being female. I do not believe it’s hateful to say so.”
It then emerged at the weekend that Rowling’s latest instalment in her Cormoran Strike detective series, published under the pseudonym Robert Galbraith, centres around a cis male serial killer who dresses as a woman to kill his cis female victims.
Meanwhile, Jedward have also spoken out to accuse Stone Roses frontman Ian Brown of “backward views” for his comments on social media about coronavirus.
The former X Factor contestants have become public advocates for wearing masks and sticking to social distancing rules, and they hit back at the 57-year-old rocker for his anti-vaccine conspiracy theory remarks on Twitter.
Brown tweeted earlier this month: “NO LOCKDOWN NO TESTS NO TRACKS NO MASKS NO VAX #researchanddestroy.”
He recently added: “So im a Conspiracy Theorist HA! a term invented by the lame stream media to discredit those who can smell and see through the government/media lies and propaganda #researchanddestroy.”
Jedward tweeted Brown to say: “Hi Ian you discredited yourself with your backward views and non logical actions.”
The twins added: “@ianbrown The Public have lost all respect and credibility for your views! Your music and cheekbones are a dream but your tweets are a nightmare.”