Until you know for certain that she actually swallowed that bone, you won't know anything to do for certain. That is quite a large object to actually swallow, and if she did, just where is it?

An X-ray should be very informative, and done tomorrow, unless you find the bone around the house meantime. Don't give her food, but all the water she may want.

If there is a puncture in the esophagus, she will rapidly go into respiratory distress, as it will allow air into her chest cavity and, at least, partially collapse her lungs.

Make another sweep of the room or area where she may have swallowed the bone and try to find it. Is there another pet that may have carried it off? If you have satisfied yourselves that there is no bone to be found, you may feel more justified in having the x-ray... tomorrow.