E.F.
When I was 4, I had exactly the same thing happen to me. Please, please, take her to a pediatric dentist. I went to a regular dentists, they didn't let my parents in the room, they used an ADULT dental dam on me -- it was AWFUL! My parents had worked so hard to get me educated about the procedure-- we even went to the dental school and looked at models of teeth and talked about cavities, and then the dentist just told me he was "going to write my name on my tooth."
You have to take care of this-- baby teeth are the placeholders for adult teeth, and poor dental health in kids is a huge risk for poor dental health in adults, but please find someone who isn't going to traumatize your daughter. Oh, and take her to McDonald's afterwords-- a fillet o' fish and a chocolate milkshake was my reward for going through all that and it still works today! :-)