My Deanda relatives (my grandmother's maiden name was Deanda) are from the Corpus Area. More specifically, they were from Jim Wells County (Nueces before 1910 and from San Patricio County in the late 1800s). Your grandmother could possibly be a first cousin to my great grandfather. Here's why... My great grandfather, Tiburcio Deanda was the son of Gabriel Deanda and Teresa Gomez. Gabriel was born on March 29, 1861 in Texas. Gabriel's father was (Jose) Tiburcio Deanda and his mother was Petra Lopez. According to census records, they were born in Mexico. My great great great grandparents (Jose) Tiburcio Deanda and Petra Lopez had several children: 1. Jesús DEANDA born circa 1850 in Mexico (married Juana Montalbo circa 1870) 2. Gabriel DEANDA born March 29, 1861 in San Patricio County Texas (married Teresa Gomez in 1876 in Refugio County Texas) 3. Crecencio DEANDA born circa 1864 4. Juliana DEANDA born 9 June 1866 in Texas 5. Antonia DEANDA born 8 Sep 1872 in Refugio County, Texas 6. Patricio DEANDA born circa 1873 7. José Tiburcio DEANDA born 11 Nov 1876 on the Puentes Ranch in San Patricio County, Texas.
There's also a "Fermina Deanda" that appears in various records from that time. But, I haven't been able to find a definite link to the family I list above.
I haven't looked into the families of those I list above, but a good place to start would be to look at the 1880 or 1900 Texas Census. See if your grandmother's name appears as the daughter of any of the males listed above (except my great great grandfather Gabriel and his brother Jesus--Jesus had no children).
Tiburcio Sr., Gabriel, and Crecencio worked for the Coleman Fulton Pasture Company in San Patricio County. I have found their names on payroll records (at the Center for American History at UT Austin) from the late 1870's early 1880's. Gabriel, in particular, was a ranch foreman who earned $50 a month in 1883.