My child is teething?

Well my 12 year old has one tooth thats growing in, its the last one and in the back. We went to the dentist, they gave her this gel to put on it, but she says it barely works and only lasts for about a half an hour and she can only use it 4 times a day. I don't know what to do because she says she can't open it very much, but she can't close it all the way either. I got her tomato soup for lunch and chicken broth for dinner so she doesn't have to chew. What can I do to help her? Is there anything I can do to make it less painful? Also is there anything I can do to make the broth taste better (its just plain chicken broth)?