Multiple realities(covers information from several alternate timelines)
June Wallace was the maiden name of the wife of Alexander Marcus. She was the mother of Carol Marcus and the grandmother of David Marcus. (Star Trek II: The Wrath of Khan; Star Trek Into Darkness)
In 2259 of the alternate reality, Carol Marcus used her mother's maiden name to board the USS Enterprise so no one would know who her father was. (Star Trek Into Darkness)
A deleted scene would have established her as having lived in England, where she raised Carol Marcus. 
The Star Trek app for smartphones and tablets revealed her first name to be "June".