The answer to the question, Finbar? is provided in an interview published when Martin Furey was still with the High Kings,
dated 27 April 2008 in The Independent. Which states:

"Martin, who is currently enjoying great success with the exciting Irish ballad group The High Kings,
is the eldest of Finbar's five children with his wife Sheila:
the others being
Aine, also a musician,
Robert, an actor and production manager for CoisCeim dance company,
Katriona, manager of the Sisley shop in Grafton Street Dublin,
and late arrival Finbar, or 'Plan B' as he is affectionately called by his dad ... "