It's very early yet: her ligaments have been playing peek-a-boo (the ones that disappear when birth is imminent), but she's been keeping to herself and breathing differently (rhythmic and heavy, like when she was in labor last year) all day.
And when I just checked on her about half an hour ago, her ligaments were gone!
We've probably still got another 12-24 hours to go, so it's going to be a long night of dozing for a bit and taking turns checking on her. (And last year, she ever-so-helpfully labored for a day and a half in first stage, then QUIT – as in totally back to normal – for a day and a half before starting over again and finally – FINALLY – having her babies. So we'll see.)
Back when we have more news (and cute baby photos)!