It looks like Marnie isn't Allison Williams' only character who is having a hard time growing up. According to this tweet from NBC's official Twitter account, Girls star Allison Williams will play Peter Pan in the network's musical show. Peter Pan will be broadcast live on NBC, just as The Sound of Music starring Carrie Underwood as Maria was last year. Williams will share the stage with Christopher Walken, who will play Captain Hook in the musical.

Williams may not be a surprising choice for a musical, but she is an unusual choice to play Peter Pan. Williams is a singer, and a pretty good one — that's her real voice belting out awkward Kanye lyrics on Girlsbut I'm unsure of whether she has the right voice for the part. Williams' voice can be best described as "pretty," almost Disney Princess-like. (Williams has expressed interest in playing Anna in a Frozen musical, and I think she would nail the part.) That's not a bad thing, of course, but Peter Pan is a bit more rough-and-tumble. Williams will be belting out songs like "I Won't Grow Up" as though she's a never-aging 12-year-old boy. I'm not sure I can picture Williams expressing her desire to climb trees.

Then again, maybe I'm biased. After all, I have spent the past three years watching Williams as Marnie, easily the most fussy and least "rough-and-tumble" of all the girls on Girls. It may be hard to picture Marnie as Peter, but maybe Williams will surprise us all with the performance of a lifetime.

Then again, I like to think that this performance was Williams' performance of a lifetime.