My wife is descended from one of William J. Heenan's brothers.
According to the 1901 census, William J. and Emma Heenan had two sons, Joseph G and William C Heenan.
Joseph G. Heenan married Margaret Cable and had at least five sons and one daughter. William C Heenan was married and lived out his life in Halifax, but I don't know whether he had children.
One of the sons of Joseph G Heenan was Fr. Gregory Heenan, a Catholic priest who died just a few years ago. He was our parish priest for a few years, a quiet and good-humored man we thought the world of.
Another of the sons became a top executive with a large telephone company in western Canada.
The daughter was still living in Halifax a couple of years ago. I think she married, but don't know her married name.
According to the website Canada 411, there is only one Heenan still listed in a Nova Scotia telephone directory. I don't know whether he is one of your relatives.
There is an Ancestry.com family tree for part of this Heenan family.