My best friends dd, 3.5, fell at preschool a couple weeks ago and split her lip and banged her top teeth. Her teeth ended up being fine, but they made several visits to a pediatric denist. One tooth was discolored and the other was very loose. The worry was the teeth might have broke off under the gum line. They ended up temporarily securing the teeth to let them firm up and heal and monitored with exrays for a couple weeks.
P.S. Lips heal quickly :)
If in any doubt it's better to have a needless dr or dentist appt than to not have a needed one.
Hope she feels better!