Bring her in and give her a good 15 minute soak in a warm sink. While she's in there clean her backside/vent area really well and gently feel around/under the vent for an egg. I haven't had an egg bound hen myself, but there are a to of threads on it so if you feel something do a search on it. From what I've read the bath will often relax them enough to pass the egg. Be sure to blow dry her (low heat) after the bath so she doesn't get chilled. Whether she's egg bound or not you should probably seperate her from the flock and keep her somewhere warm where you can monitor her eating/drinking/pooping.