My 3 year old is getting new teeth. What can I give her fir pain?

Tylenol, (acetaminophen) teeth rings. Unfortunately teething hurts. Teething rings are the best- they are water filled rings you freeze and they bite on them, and the ice/cold helps sooth their gums. You can also give tylenol (acetaminophen) short term.
Chew on cold objects. I would first see if allowing her to chew on a cold washcloth or one of the teething rings designed to stay cold would be of help. You can also massage her gums to see if this would give her some relief. If this didn't work, i would recommend a weight appropriate dose of Acetaminophen or ibuprofen. I don't recommend any topical anesthetics such as ambesol or baby orajel.
Children's tylenol (acetaminophen) Children's tylenol (acetaminophen) works well. Read the package directions for the proper dosage for her weight. Ask you dentist or pediatritian to be sure.