Best Food Places for 8/9 Year olds

I will be taking my niece who is almost 9 to the Perot Museum on a Monday. I’m trying to decide where we should go for lunch… if we should just eat in the museum or if there is somewhere cool I can take her before or after that would be really special. A special milkshake bar or a special restaurant that kids really enjoy… I’ve never been in Dallas before. I want to make it a very special and exciting day for her.