Allison Williams Joins Instagram

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Her username is "aw."

On the heels of being cast as Peter Pan for the NBC live production, Allison Williams has more news to share: She has joined Instagram.

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For her first post, the Girls actress chose an adorable picture of herself, dressed in a Peter Pan costume. "Thrilled to be playing Peter Pan live on NBC in December. I've been rehearsing for a REALLY long time," teased the 26-year-old star, who will star as the title character on the Dec. 4 broadcast.

If her photo doesn't make you want to say "aw," let her Instagram handle do it for you.