Rosianna Halse Rojas is John Green's personal assistant. She filled in for him on Vlogbrothers on July 2, 2013, during his paternity leave following the birth of his daughter Alice, as well as managing his Twitter feed during that time. She has also been credited as co-writer on several Crash Course US History videos alongside John and Raoul Meyer.

Rosianna currently lives in Indianapolis, IN, but is from London, United Kingdom.

External Links:
Rosianna on Youtube: Rosianna Halse Rojas