Mrs May's meeting with the Saudi King comes after a princess became the first female ambassador to serve as a top diplomat in the US.
The kingdom's strict guardianship laws were highlighted last month after teenager Rahaf Mohammed Alqunun, made a dramatic escape from the country, citing an abusive family and state-sponsored oppression.
She is familiar with U.S. politics and society, having lived in Washington when her father Prince Bandar was ambassador (1983-2005), and studied at USA universities, the National website reported.
She is also known for her advocacy work around women's rights, increased women's participation in sport, and breast cancer awareness.
Mrs May joined King Salman for the EU-League of Arab States Summit in Sharm El-Sheikh where she planned to urge him to use his influence to encourage Yemeni parties towards peace amid the Kingdom's strained relationship with the West. Crown Prince Mohammed bin Salman was absent from the summit.
The Post, citing unnamed sources in November, also reported that USA intelligence agencies reviewed a phone call that Prince Khalid had with Khashoggi, in which he allegedly told the writer he'd be safe going to the consulate to retrieve the documents he needed to get married.
Princess Reema will replace Prince Khalid bin Salman, a son of King Salman and a younger brother of the Crown Prince, who took the post in 2017. She will be the first Saudi woman to head a diplomatic mission in any form, the Saudi Press Agency reported.
Indian Air Force violated LoC, claims Pakistan
Pakistan's Prime Minister Imran Khan on Sunday said his Indian counterpart Narendra Modi should "give peace a chance". There are also unconfirmed reports that clashes have erupted on the ground along the Line of Control.
The U.S. Treasury sanctioned 17 Saudis in October over the Khashoggi murder, and more recently the Congress has pushed to blame the crown prince for the killing and end U.S. support for the Saudi-led coalition in Yemen.
Princess Reema is a graduate of George Washington University, and has served as an adviser to the Crown Prince office.
Princess Rima, the daughter of a former long-time ambassador to the United States, has been a leading advocate of female empowerment in the kingdom, which has faced intense criticism over the recent jailing of women activists - and subsequent claims of sexual abuse and torture of some of them in detention.
His naming comes as Saudi Arabia remains mired in its years-long war in Yemen, which also have strained USA relations to the kingdom.
"Prince Mohammed has struggled to delegate authority within this file which has rendered some efforts -- chiefly military reform - stagnant, and Prince Khalid's appointment may be an attempt to reinvigorate these initiatives".
Khashoggi's killing has refocused attention on the Saudi-led coalition's bombing campaign in Yemen, which is gripped by what the United Nations calls the world's worst humanitarian crisis.