The following members of a Cowin family lived in Douglas So you could please Donna, check DBC and Braddan New Cemetery. (I looked at lawsonmicrobmd first but didn't find burial dates for 3 of them. Perhaps they are recorded in the Douglas Borough Crematorium.
David Edward Cowin buried 20th April 1976, Braddan. He may have married 1928 Douglas (wife's name unknown) and/or Thelma Killey 1948, Braddan
Wilfred Kelly Cowin born 1905. Burial not found but he married an Elsie Gawne who was buried either 22nd Oct. 1982 DBC, age 82 or 1935, age 24 Braddan.
John Alfred Valentine Cowin was buried 3rd April, 1961 DBC
Charles Bertram Cowin born Douglas 1909. Not certain of his burial. He married Evelyn Simpson in 1950 and had 2 sons born in 1953 & 1955 Douglas.
Leonard Hugh Cowin born Douglas, 1914. Burial not found. He married Joan Margaret Walton 1946, Douglas.
(Tried to contact you directly but the emails are not getting through).
Thanks for any information that you may find.