Girls star Allison Williams finally has joined Facebook, just days ahead of Thursday night’s live broadcast of the Peter Pan musical on NBC. Her accession to the biggest social media platform out there is further boosting a burgeoning online presence for the updated show featuring Williams as Pan and Christopher Walken as Captain Hook.

The revamped show — which has its concerned detractors, including Deadline’s Broadway critic Jeremy Gerard — has seen #PeterPanLive hashtags spiking on social media in the past three days, to more than 4,000 today, since a ‘Making of’ special about the show ran, said Marc Karzen, CEO of RelishMix, a consulting firm that tracks film and TV properties on Twitter, Facebook and YouTube.

The PeterPanMusical Page on Facebook launched four weeks ago and is at 517,000 likes. That might not seem like a big number for a show filled with big (production) numbers, Karzen said. But for a broadcast TV show, especially a one-off like this special live broadcast, that’s terrific.

Allison Williams 2Meanwhile, Williams launched her own official page on Facebook just last Thursday, and has 6,000 followers and counting, not bad in such a short time, Karzen said.

That said, it’s more than a bit surprising that it took this long for Williams to join the social-media parade that seems nearly de rigeur particularly for young performers hoping to build a durable audience. Williams has had a key role on HBO’s Girls since its 2012 launch and also has appeared in shows such as The Mindy Project, The League and the royal biopic series Will & Kate: Before Happily Ever After.

Meanwhile, she got a little shout-out from her dear old dad, Brian Williams, when he appeared Tuesday night on The Tonight Show Starring Jimmy Fallon to celebrate 10 years as the NBC Nightly News anchor. As Deadline posted this morning, Williams and Fallon did a slow-jam comical/musical interlude reading the news on immigration policy.

But the elder Williams (“Peter Pan Senior,” as Fallon gigs him) also slipped in a proud mention of his own Girl Who Never Grew Up. Here’s the tweet NBC posted of that part of their performance:

NBC also posted a little soft-shoe video of Walken prepping for his duel/duet with Pan.

And for fans who can’t get enough of the behind-the-scenes stuff, NBC collaborated with Maker Studios‘ online star Alex G (she has 1.3 million YouTube followers) and DJ Tay James (he has 695,000 Twitter followers) to create a very entertaining music video.

The video mashes up a high-energy take on music from the show with cast members and just plain folks dancing along. It’s quite charming, and has been seen by nearly 295,000 people in its first day online. Here’s the video: