I didn't know if they were born before of after my father's birth. However, I found a couple of death record abstracts on the Family Search, Record Search page that confirmed that they were born after my father:
Lily Florence Baca died on 30 August 1933, while Raymond Eugine (sic) Baca died on 15 November 1934. My father, Robert Carlos Baca, was born on 6 April 1932. My aunt Teresa once showed me where my father's two brothers and sister were buried - there is no gravestones, just a few stones mark the spot in the San Miguel Cemetery.
I also searched for a record for another uncle, this time a son of my maternal grandparents Santiago Baca and Pablita Zimmerly (remember, my mother's maiden name is also Baca.) Estevan Baca, who was named after my great grandfather Estevan Zimmerly, died a little over a month after he was born. The family story was that the doctor did not know how to use forceps and crushed my uncle's spine. My uncle Estevan, or Steven as the gravestone has his name, is buried in my family's plot at the San Miguel Cemetery in Socorro, New Mexico.
Below is the abstract that shows that he died on 5 May 1938 in Socorro, Socorro County, New Mexico. I didn't know until I found this record yesterday that his middle name was Carlos.
Coincidentally, today is El Dia de los Muertos - the Day of the Dead.