Patti Flynn, who lost her father and two brothers in WW2, spent 26 years fighting for the memorial.
Patti Flynn, 81, said the sacrifices of servicemen and women from diverse backgrounds had been "forgotten" and deserved special recognition.
She was born two years before the outbreak of World War Two, in what was then known as Tiger Bay in the docks area of Cardiff, and said she still remembered bombs falling in her street.
Her father Wilmott Young - who was born in Jamaica but married a Welsh woman after coming to south Wales as a seaman during the coal boom - enlisted to the Armed Forces, along with his two sons who lied about their ages so they could join up.
Ms Flynn's brother Jocelyn Young was aboard a merchant navy boat that was torpedoed in the North Atlantic in 1940 and her father, also in the merchant navy, died a similar way a year later.
In 1944, Patti lost her older brother Sgt Arthur Young, a wireless operator in the RAF, when his damaged Lancaster bomber crashed returning from France.
"People have asked me where I came from but they don't realise my ancestors have been here since the early-1900s and my father and brothers died for their country," said Ms Flynn. "But for so many from ethnic groups, their service has largely been forgotten and not acknowledged.”
A plaque was unveiled at the Welsh National War Memorial in Cardiff on Saturday in a ceremony with 200 people.
