In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

The seven young actors who became part of cinematic history when they were cast as the von Trapp children in Rogers & Hammerstein's The Sound Of Music in 1965 have grown to become lifelong friends in the fifty years since the famous film's release. Known as The SoM 7, they formed their own sort of family over the months of making the musical. Their parents befriended one another as the young performers traveled to Austria for filming, and the actors themselves have remained close for decades. 'We're beyond friends. We're second family,' said Kym Karath, who played the youngest von Trapp, Gretl. 'As adults, we were deeply bonded, so our lives have really interwoven with each other.'The 1965 Oscar-winning film adaptation of the Rodgers & Hammerstein musical The Sound Of Music is celebrating turning 50 this yearThe actors who starred as the von Trapp children have remained close friends over the five decades since they traveled to Austria together'We're beyond friends. We're second family,' said Kym Karath, who played the youngest von Trapp, Gretl 
 Question:Kym Karath was only 5 years old when she played _.
Gretl