The following data is extracted from History of San Mateo County.
Belonging to one of the oldest and most representative families of the county, Miss Mercedes Sylvia has much to remember and to be justly proud of in the part that her forbears took in the settlement and upbuilding of San Mateo County in the early years when there were hardly any settlers, inadequate transportation and no conveniences to speak of.
She was born in San Bruno, July 23, 1887, educated in San Mateo county, and has continued to live here ever since. Provided with ample means that would enable her to live anywhere she chose, she has nevertheless elected to remain in the county of her birth-which speaks much for the charm that this beautiful section of country never fails to weave about all who live within its limits.
Her father, Custodio Silvia, now deceased, lived a most useful life, and bequeathed to his daughter an estate of sixty-three acres of very valuable land in San Bruno which is constantly increasing in value.
Miss Silvia is deeply interested in church work and devotes much of her time to furthering the cause of the Catholic faith in San Bruno. In 1909, shortly after San Bruno had been made a separate parish, the Silvia family bought a piece of ground 50x100 feet, where the church now stands and presented it to the church, while the San Bruno people collected $1500. The little mission church is a familiar and beautiful object to all who pass along the Camino Real. It is called the "Mission San Bruno;" and is in part a monument of the generosity of the Silvia family of which Mercedes Silvia is the only heir.
Source: History of San Mateo County