The American novelist Jennifer Cody Epstein has said that she “fundamentally misunderstood Charlie Hebdo’s mission and content” when she put her name to a letter condemning PEN’s decision to honour the magazine with an award.

Epstein was one of more than 200 writers who signed a letter disassociating themselves from PEN American Center’s choice of the French satirical magazine, where 12 people were killed by gunmen in January, as winner of its “Freedom of Expression Courage award” last month. The writers, who also included Peter Carey and Michael Ondaatje, argued in their letter that the choice of winner was “not simply conveying support for freedom of expression, but also valorising … material that intensifies the anti-Islamic, anti-Maghreb, anti-Arab sentiments already prevalent in the western world”.

But in a move praised by The Satanic Verses novelist Salman Rushdie, who has thrown his weight behind PEN and Charlie Hebdo since the start of the controversy, Epstein has asked for her name to be removed from the petition.

“The 1st protester to admit she was completely wrong,” tweeted Rushdie on Sunday. “Respect to Jennifer Cody Epstein for doing the honourable thing & admitting she made a mistake about #CharlieHebdo. Will others follow her?”

The 1st protester to admit she was completely wrong: Jennifer Cody Epstein's letter to the anti-Charlie Hebdo faction http://t.co/jvI4UQoGD2 — Salman Rushdie (@SalmanRushdie) May 31, 2015

In a letter to her fellow signatories published in full by the writer Ophelia Benson on Free Thought Blogs, Epstein wrote that she was “misinformed and (quite frankly) wrong” when she made her decision to add her name to the list.

She now believes that Charlie Hebdo’s “controversial images – while arguably tasteless, offensive and not even particularly well-drawn – sprang from satire, not hate”.

“It is a profound and crucial difference: if one is to argue for freedom of speech there can be no caveats, no asterisks, no fine print qualifying that ‘freedom’ only applies to expression we don’t consider too upsetting, or doesn’t enrage right-wing fundamentalists with guns,” her letter reads.

She adds that she was “also under the misassumption that Hebdo disproportionately lampooned Islam”, and points to an article by Michael Moynihan in the Daily Beast, in which he highlights the fact that Charlie Hebdo has had more anti-Christian covers – 21 – than anti-Islam – seven – in the last 10 years.

“As a writer whose work is largely predicated on diligent and careful research, I am reluctant to admit that in this case, I didn’t do enough of it before sending my name out into the Cloud,” writes Epstein. “Unfortunately, though, that is the conclusion to which I’ve been forced to come, and I thought it best to acknowledge it publicly and head-on rather than disingenuously pretending otherwise.”

Last month, Charlie Hebdo’s editor-in-chief Gerard Biard accepted the PEN award to a standing ovation at a gala in New York. “Tonight’s award reflects [Charlie Hebdo’s] refusal to accept the curtailment of speech through violence,” said PEN president Andrew Solomon at the event. “We defend free speech above its content. Muteness is more toxic than speech. Silence equals death.”