I am Heather, an American in Spain, fluent in both English and Spanish, with basic knowledge of Gallego as well.
Since the age of 5 I have spoken both languages, because I grew up in Andalucia (southern Spain) and attended spanish schools, but at the same time English was always spoken at home. I also attended an English school from 6th grade up through highschool. I returned to the US for college, and worked in San Francisco for a couple of years before returning to Spain again.
I have been living in Galicia since 1997.