There are links between the Christian and Arab families in Spain, but no proven modern descents from the Arabs. Lots of interesting possibilities, though.
The wife of Musa ibn Fortun and of Íñigo is unknown.
“All we know from the primary record is from ibn Hayyan (as abstracted by Levi Provencal and Garcia Gomez) who reports that Wannaco ibn Yannaco (from context, identical to the man known to historians as Inigo Arista) joined his half brother on the mother's side, Musa ibn Musa, in rebellion. Later in the decase, his brother Fortoun ibn Wannaco, the foremost 'knight' of Pamplona, was killed supporting his half-brother Musa. Thus we have three siblings, Musa by Musa, and Fortun and Inigo by Inigo. We also know that Musa had a sibling Lubb ibn Musa (from ibn Hazm), but no indication of his mother is given. Finally, Fortoun ibn Musa (k. 802) and Mutarrif ibn Musa (k. 799) have been suggested as siblings, but they seem significantly older than Musa ibn Musa, so I doubt they were children of Inigo's mother. (Of course, the new reconstruction would put them two generations earlier.)” Todd A. Farmerie, New reconstruction of early Banu Qasi at soc.genealogy.medieval (Feb. 4, 2011).
https://groups.google.com/forum/?hl=en#!searchin/soc.genealogy.medi...
There is a lot of early Spanish material at soc.genealogy.medieval, most of it not yet touched by Geni users.