Christmas Witches
Here's one birthday I wasn't aware of when I compiled the anime birthday list for December. It's Francesca Lucchini from "Strike Witches," as seen above in this nice & festive image. The naughty loli, my fav character, from the hit Gonzo series celebrates her big day on Christmas Eve it seems. So does that mean she's now turned 13? Cue the otakus who'll say "She's too old now."
Happy Birthday, Francesca! & a Merry Christmas!
Source: http://www.sankakucomplex.com/2008/12/25/christmas-witches