France opened a murder enquiry in late August after Arafat's family launched legal action following reports he may have died from radioactive polonium near Paris in 2004.
The source told AFP on Wednesday that Suha, a resident of Malta, had met with investigators in the Paris suburb of Nanterre, where the family's complaint was filed. No other details were disclosed.
French investigators are due to arrive on November 26 in Ramallah, where the former Palestinian leader is entombed, as part of a probe they are conducting with experts from a Swiss radiation institute.
Arafat's family has agreed to the exhuming of his remains for testing in the investigation.
The iconic Palestinian leader died in a French military hospital near Paris on November 11, 2004. French doctors were unable to say what had killed him and many Palestinians believe he was poisoned by Israel.
France opened the inquiry after Al-Jazeera television broadcast an investigation in which the Swiss experts said they found high levels of radioactive polonium on Arafat's personal effects.
Polonium is a highly toxic substance rarely found outside military and scientific circles. It was used to kill former Russian spy turned Kremlin critic Alexander Litvinenko, who died in 2006 in London shortly after drinking tea laced with the poison.