The 9/11 Commission Report states in footnote 122: "We have found no evidence that Saudi Princess Haifa al Faisal provided any funds to the conspiracy, either directly or indirectly.".
After the September 11 attacks, Princess Haifa was investigated for a sequence of payments allegedly made to a Saudi national by the name of Omar al-Bayoumi.
[7] In April 1998, Osama Basnan, a Saudi national living in California, wrote to Haifa requesting money for his wife's needed thyroid surgery.
At some later point (accounts vary as to when; dates between November 1999 and March 2000 were given, and a Saudi government official put the onset at 4 December 1999),[8] Haifa began sending monthly cashier's checks to Dweikat of either $2,000 or $3,500, transporting them through Riggs Bank.
[10] (This sort of charitable donation known as Zakat from members of the House of Saud to Saudi nationals living abroad is not particularly unusual.