She oughtta be just fine. They digest bones, claws, beaks and teeth. A bit of wood isn't really worrisome. If you're still concerned, next time, just pick off the bigger pieces as she's swallowing - they can't bite you when they have a mouth full of rodent. Some higher strung animals will spit it out but many will continue swallowing as long as you're not disturbing them overmuch. Try not to poke the snake or jostle the prey.