Assuming is bad way to go - we have a couple in our church with a very Spanish sounding name (Garcia)- and the parents and kids are all blonde hair, with blue eyes, and the family has been in the country for several generations. I have a student with the last name of Jones - yep, you guessed it, Hispanic.
That and the fact that if they bothered to click on the link, it clearly stated that she was a native Californian.
My husband is Hispanic. Puerto Rican and Brazilian. Our last name is Ryan. Back several generations ago, his Puerto Rican great grandmother married an Irish seminarian who had come to Puerto Rico to work in a Catholic Mission. The name has carried through the next 5 generations, even though there is very little Irish in their background.