Ivanka Trump is working out of a West Wing office at the White House and will get access to classified information, although she is not technically a government employee, according to an official.
Since Donald Trump took office, his eldest daughter has been a visible presence in the White House, where her husband, Jared Kushner, is a senior adviser.
On Friday, she participated in a meeting on vocational training with the president and German Chancellor Angela Merkel.
Jamie Gorelick, a lawyer and ethics adviser for Ms Trump, said the first daughter will not have an official title, but will get a West Wing office, government-issued communications devices and security clearance to access classified information.
Mr Gorelick said she would follow the ethics rules that apply to government employees.
"Our view is that the conservative approach is for Ivanka to voluntarily comply with the rules that would apply if she were a government employee, even though she is not," said Mr Gorelick, who also helped Mr Kushner with the legal strategy that led to his White House appointment.
"The White House Counsel's Office agrees with that approach."
Ms Trump's role has already come under scrutiny because there is little precedent for a member of the first family with this kind of influence.
A source said she believes she can offer more independent perspective to her father by not serving as a White House staffer.
A popular surrogate for her father on the campaign trail, she moved her young family to Washington at the start of the administration and signalled plans to work on economic issues, like maternity leave and child care.
In a statement, she said: "I will continue to offer my father my candid advice and counsel, as I have for my entire life."
Federal anti-nepotism laws prevent relatives from being appointed to government positions, but the Justice Department's Office of Legal Counsel recently said the president's "special hiring authority" allowed him to appoint Mr Kushner to the West Wing staff.
Mr Gorelick noted the office also made clear that the president could consult family members as private citizens, arguing that this is what Ms Trump will be doing.
The first daughter has sought to distance herself from the Trump Organisation and her lifestyle brand, which offers shoes, clothing and jewellery. She has removed herself from executive roles and will have a more hands-off approach to the brand - though she will still get certain information and will have the power to veto new deals if they raise ethical red flags.
Richard Painter, a University of Minnesota law professor who served as George W Bush's chief White House lawyer on ethics, said Ms Trump is effectively working as a White House employee.
He said that "means that she, like her husband, has to follow the rules. It's not a huge deal if she stays out of things that affect her financial interests".
Mr Painter said that means she should avoid anything to do with foreign trade with countries where her products are made, as well as recuse herself from real estate matters, given Mr Kushner's family real estate business.