Castillo then played the 2011 Pan-American Cup being awarded with the "Best Libero" and "Best Digger" awards, also winning the silver medal with her national team. She then took part of the 2011 Junior World Championship held in Lima, Peru. She helped her Junior National team to reach the 5th place in the tournament. Brenda won the silver medal and the Best Libero, Best Digger and Best Receiver awards at the 2011 NORCECA Championship, held in Caguas, Puerto Rico. She was also awarded the Best Libero, Best Digger and Best Receiver awards at the 2011 Pan American Games where her team finished in fourth place.