While I'm not her biggest fan, me and Francine were doth born on January 22nd. I find her slightly annoying but I don't think I could completely hate her simply for the fact we do share our birthdays.
I sadly have no birthday buddy in AC. Closest is that Dotty's birthday is the day after mine, and Midge's the day before. Oddly, I've had them both in the same town before, but I restarted before it got to our birthday month.