If your dog seems to be choking, use a flashlight to check her throat. If you see and can easily remove the object, do so.
If you can’t see the object but are certain your dog is choking, you might need to perform a modified Heimlich maneuver. It is important to get proper training for this, as it can cause serious injury if done incorrectly. Many humane societies and animal welfare organizations offer classes on pet first aid, that include the Heimlich maneuver, CPR, and techniques for dealing with serious injury and poisoning.