Her dad was (former) Mossad. The conspiracy theory is that she was a Mossad agent who worked to gather dirt on powerful people around the world. Basically, get photos of the POTUS banging a 14 year old, and you can use it to pressure him into doing things that you want.

https://en.wikipedia.org/wiki/Robert_Maxwell#Mossad_allegations;_Vanunu_case

The Foreign Office suspected Maxwell of being a secret agent of a foreign government, possibly a double agent or a triple agent, and “a thoroughly bad character and almost certainly financed by Russia”. He had known links to the British Secret Intelligence Service (MI6), to the Soviet KGB, and to the Israeli intelligence service Mossad.[58]

Shortly before Maxwell’s death, Ari Ben-Menashe, a former employee of Israel’s Military Intelligence Directorate, approached a number of news organisations in Britain and the US with the allegation that Maxwell and the Daily Mirror’s foreign editor, Nicholas Davies, were both long-time agents for Mossad. Ben-Menashe also claimed that, in 1986, Maxwell informed the Israeli Embassy in London that Mordechai Vanunu revealed information about Israel’s nuclear capability to The Sunday Times, then to the Daily Mirror. Vanunu was subsequently kidnapped by Mossad and smuggled to Israel, convicted of treason and imprisoned for eighteen years.[59]

https://en.wikipedia.org/wiki/Ghislaine_Maxwell

In November 1991, Robert Maxwell’s body was found floating in the sea near the Canary Islands and Lady Ghislaine.[38] Soon afterwards, Ghislaine flew to Tenerife, where the yacht was berthed, to attend to his business paperwork.[26] She attended her father’s funeral in Jerusalem alongside Israeli intelligence figures, president Chaim Herzog, and prime minister Yitzhak Shamir, who gave his eulogy.[39][40] Although a verdict of death by accidental drowning was recorded, Maxwell has since said she believes her father was murdered,[41] commenting in 1997: “He did not commit suicide. That was just not consistent with his character. I think he was murdered.”[42] After his death, Robert Maxwell was found to have fraudulently appropriated the pension assets of Mirror Group Newspapers, a company that he ran and in which he held a large share of ownership, to support its share price.[43] Pension funds in excess of £400m were said to be missing, and 32,000 people were affected.[44] Two of Maxwell’s brothers, Ian and Kevin, who were the most involved with their father in daily business dealings, were arrested on 19 June 1992 and charged with fraud related to the Mirror Group pension scandal.[45] The brothers were acquitted three and a half years later in January 1996.[46]

https://www.middleeastmonitor.com/20200106-jeffrey-epstein-was-blackmailing-politicians-for-israels-mossad-new-book-claims/

The claims are being made by the alleged former Israeli spy Ari Ben-Menashe in a soon-to-be-released book “Epstein: Dead Men Tell No Tales” in which he said that he was the handler of Ghislaine’s father Robert Maxwell, who was also an Israeli espionage agent and was the one who introduced his daughter and Epstein to Mossad.

“See, fking around is not a crime. It could be embarrassing, but it’s not a crime,” Menashe wrote in the book. “But fking a fourteen-year-old girl is a crime. And he was taking photos of politicians f**king fourteen-year-old girls—if you want to get it straight…They [Epstein and Maxwell] would just blackmail people like that.”

https://www.jpost.com/israel-news/jeffrey-epstein-may-have-had-links-to-israeli-leaders-the-rolling-stone-674244

The report’s author, Vicky Ward, cites four separate sources, some of which are considered more reliable than others. According to the report, Robert Maxwell - a conduit between the Israeli government and other governments during his life - introduced Epstein to Israeli leaders. Maxwell invested tens of millions of dollars into Israel’s economy, serving as a point man for its governments. According to a Washington Post article published after his death, he visited Jerusalem once a month and even considered purchasing the Beitar Jerusalem soccer team. However, Epstein claimed in a 2002 interview with Ward that he had never met Maxwell. He did, however, have a well-known relationship with his daughter Ghislaine who is currently awaiting trail for charges related to helping Epstein in alleged sex-trafficking of minors. Epstein did visit Israel in 2008, almost moving permanently to avoid jail time. He decided against it, however, facing 13 months in jail, before being released on July 22, 2009. According to The Rolling Stone report, Epstein spent the last years of his life bragging to people, including journalists, that he was an advisor to an assortment of foreign leaders - including Israel. The article states he was known as a “hyper-fixer,” somebody who can go between different cultures and networks.