I suspect that the name came from the famous Black Panther prison break in the 1970’s. Soledad State Prison in California
That was 1970.
She was born in 1966.
Plus, she's not really African-American. Her father was White and Australian, her mother, Black and Cuban.
But her mother came over in 1958, before Castro took over. That may help account for Soledad's skewed view of Castro, but it's a strange one for a Cuban-American to have.