It's just one of those things that comes together. Moira's been on the island long enough to settle into a rhythm here and she's never let the strangeness of her life stop her from pushing ahead. Jean's birthday is coming up, so Jean gets a birthday party, because they're all in one place and, for once, relatively safe. No one's dead or dying, no one's liable to come crashing through the window to break things up with a fight. Spirits might be high, but that's as it ought to be, and she's here to make sure matters stay as low-key as they can be with the X-Men involved.
After some talk about where's best, she's managed to get permission from Pepper to make use of Tony's home, which is where, apparently, they celebrated last year, so it feels appropriate. Jamie suggested film noir for a theme, and since Moira hadn't even thought about one, she's gone on with that; it seems like something Jean will appreciate. There's music and cake, some light refreshment she's managed to assemble, and if there's one advantage to life on the island, she thinks, it's that they might all get through a party intact.
[Set to June 9th. See
here for details and tag each other, have fun. :D]