Robert
I believe your father was acquainted with my Uncle, Bill Lambden, and, yes my late grandmother Crowe would have been aware of a blood relationship with the Corletts of L-y-Y, albeit very distant. My great grandmother Eliza Ann Corlett of Cooil Roi, Lonan was descended from the second marriage of Sumner-General Thomas Corlett of Ballakoig, Ballaugh who shared Bishop Wilson's imprisonment in Castle Rushen, and supervised the dragging of Katherine Kinrade across Peel harbour. The Corletts of L-y-Y also descend from the Sumner-General's second marriage, but from the youngest son Robert, whereas we come from the 4th son, Ewan, soldier and joiner in Douglas. Ewan's claim to fame was that he bought part of the Crowville trough from his cousin at Lewaigue and and planted the Island's first commercial plantation there. If you can get into the Loughan-y-Yeigh descent, then you can share the Fletcher ancestry which comes through the Vicar Allens of Maughold.

Just managed to look at the Administration of Thomas Cowle of Bride, d. 1813. Only child, daughter Ann under age. Widow Eliza disclaimed administration. Uncle T.A.Corlett on mother's side and gr-uncle Wm Christian Junr on father's side were guardians etc.
Re-reading Mrs C. Radcliffe on Ballavair, this daughter Ann was the heiress to the farm and on marriage took it into the LaMothe family. I recall they were using the surname Corlett.

Still looks pretty likely that she re-married into the Ballakie family.