I am also searching for information on Xavier family from Portugal. My great-grandfather, Antonio Joaquin Xavier, born 1861 or 1862, had his name changed to Antonio Xavier Joaquin by immigration officials (they couldn't spell Xavier, as he pronounced it "Chev-yay"). According to census records, he emigrated in 1869, having possibly been a cabin boy.
My Great-grandmother, Mary Joaquin, also a mystery, different maiden names from different family members . My mother (Mary's grand-daughter), remembers her saying it was "Sousa", another family member says she was told it was Estrella. Found a Marriage certificate, from 1892 for Antonio and Mary (Maria) found on FamilySearch.org says Maria Piedade De Ferreria de Souza, and cannot find birth certificates for any of the 4 children (Anthony b.1893, Manuel, b. 1894, Joseph, b. 1896 and Mary, b. 1898). They lived in California, primarily in and around San Francisco, Morgan Hill, Burnett, San Jose, Santa Clara County and Alameda).
She spoke 5 languages (Portuguese, English, French, Spanish and some Mandarin), very intelligent, worked as a Supervisor at a cannery in San Francisco before she was married.