has she acted on stage as well?
Yes, her Broadway debut was in "Of Mice and Men"
Leighton Meester
Broadway debut in "Of Mice and Men" 
who does blake lively marry in gossip girl Penn Badgley which episode is titled g.g in this tv series? The thirteenth episode what did this episode centre around? The wedding of Blair Waldorf to Prince Louis Grimaldi can you tell me where this scene was shot? The St. Regis Hotel where is it located? New York who owns this hotel? UNANSWERABLE who played the two characters you mentioned above? Leighton Meester and Hugo Becker can you name any other films where the former has featured in? "Killer Movie" (2008), "Country Strong" (2010), "The Roommate" (2011)
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Leighton Meester [SEP] Introduction
Leighton Marissa Meester (born April 9, 1986) is an American actress, singer, songwriter, and model. She is best known for her starring role as the devious socialite Blair Waldorf on "Gossip Girl" on The CW (2007–2012). She has also appeared in films such as "Killer Movie" (2008), "Country Strong" (2010), "The Roommate" (2011), "Monte Carlo" (2011), "The Oranges" (2011) and "The Judge" (2014). Meester made her Broadway debut in "Of Mice and Men" (2014). She portrayed Angie D'Amato on the ABC sitcom "Single Parents" (2018–2020). In addition to acting, Meester has ventured into music. After a featuring in top ten "Billboard" Hot 100 single Cobra Starship's "Good Girls Go Bad", she released her solo singles under Universal Republic label "Somebody to Love" in 2009 and "Your Love's a Drug" in 2010.