Complex sentence: Rodriguez-Trias's mother was a school teacher in Puerto Rico, however in New York she was not able to get a teacher's license because, at that time, bilingualism was considered a handicap.
Split into simpler sentences: Rodriguez-Trias's mother was a school teacher in Puerto Rico. However in New York, she was not able to get a teacher's license because, at that time, bilingualism was considered a handicap.