I confess to harboring a secret hope that she might be born on Bilbo and Frodo's birthday. I know I would have enjoyed that for myself, although I'm happy with my actual birthday which is also my dad's (and a great-grandfather's!). But still no signs so far that she's going to make it out today.
Turns out that those who care as much or more than me about such things have figured out that, due to differences between the hobbits' Shire Reckoning calendar and ours, September 22 in our calendar isn't actually their birthday anyway -- it was September 13, this year (due to this being a leap year). Oh well.
Shire Reckoning, by the way, has always seemed eminently more logical than our cobbled-together Gregorian, but the hobbits' old-school season-based holidays (Midsummer, Yule) that don't belong to any months would, I suppose, confuse too many people used to our modern three-day-shopping-weekend system.