My 2 in a half s been sick with a real bad cough and stuffy nose and I notice that she's shivering is that normal and grinding her teeth. She doesn't feel cold

What is her temperature? Some children will shiver due to a fever or due to a lower than normal temp. Could be due to an infection. I would take her to her doctor to be examined as there are many possible causes, some that would require treatment. At her age, it is always best to have any symptom out of the norm checked.