Attorney Bobbi Sternheim is named in filings with a US District Court as counsel for Ms Maxwell, who is awaiting trial on charges of conspiring with Epstein to sexually abuse young girls, which she denies.
Law firm Fasulo Braverman & Di Maggio lists Ms Sternheim as a "super lawyer" who has tried death-eligible cases of organised crime, international terrorism, and capital murder, as well as civil cases against the US Bureau of Prisons, the Mission of Saudi Arabia, and former first lady of the Philippines, Imelda Marcos.
But she is best known for representing Khaled al-Fawwas, the London-based spokesman of bin Laden, in a 2015 trial over the 1998 bombings of two US embassies that killed 224 people - including a dozen Americans.
In defending Mr al-Fawaz, who was sentenced to life for the Tanzania bombing, Ms Sternheim said he was denied justice after being extradited to the US from London in 2012.
"Trying a pre-9/11 terrorism case in a post-9/11 era within blocks from the World Trade Center ensured that Mr al-Fawwaz could never receive a truly fair trial by a truly impartial jury," she said outside the court, according to contemporary reporting by the NY Post in 2015.
Ms Sternheim also represented Minh Quang Pham, who in 2016 was sentenced to 40 years prison for plotting to blow up London's Heathrow Airport.
Neither Ms Sternheim nor law firm FB&D immediately responded when contacted to comment on the appointment by Ms Maxwell, which was first reported in The Mirror.
Ms Sternheim is the former head of the New York Women's Bar Association, and remains the first and only female recipient of the New York Criminal Bar Association's Award for excellence, according to FB&D.
She holds "top secret" and "sensitive compartmented information" clearance for access to certain classified government information, and has represented defendants facing international extradition.
Ms Maxwell, 58, is in custody in Brooklyn awaiting trial on sex trafficking charges due to take place next year.
She has also hired Christian Everdell, a former assistant US attorney who helped prosecute Mexican drug lord "El Chapo".