Hello and thank you for asking your question on just answer.
How long has she been coughing?
Does she have any nasal drainage or sneezing?
Does she have a productive cough or is she coughing up anything?
Is she still eating and drinking?
If you squeeze up and down on the trachea, in her throat, does that make her cough?
Is she still playing and active?
Can you lift up her lip and check her gum color please?
If she coughs when you press on her trachea then it is infectious tracheobronchitis or kennel cough. Good detective work on your part.
Kennel cough is a layperson's term for upper respiratory infection or infectious tracheobronchitis. I know she has had the vaccine to prevent it. She may have picked up a different strain then the one she was vaccinated with. It is similar to us humans getting the flu shot. It will prevent the flu as long as we were vaccinated with the correct strain of flu virus.
I would try giving her plain robitussin every 6 hours as needed for coughing. If she is about 20 pounds, you can give her 1/4 to 1/2 teaspoon every 6 hours. When you take a shower, bring her into the bathroom and steam out her respiratory tract. You can run a humidifier for her as well. You can take her temperature with a rectal thermometer. Normal temperature for a dog is 100 to 102.5 degrees fairenheit.
If her cough worsens or becomes producive, she stops eating, she has difficulty breathing, or her gums look pale, then she should see the vet.
I hope this helps.