Hi Lara. The best source of Ardnabie family history is the work of F. R. McDonald (Francis Ross). He wrote an early genealogy volume, and a few years ago completed a beautifully illustrated and documented massive volume. I don't know how locateable it is. I have a copy and will post the isbn info, full title, etc. when I have located the book in my library. There are some errors in Duncan's version even though he cites F. R. McDonald as the source.

PS There is an outline report of John Dhu Macdonell (Ardnabie) already posted on the Glengarry Genweb which might be of assistance.
Good luck,

Evelyn Goulet, Castle Tioram
Finlaggan Councillor
Clan Donald International
Host, Glengarry Genweb