Sometimes the media influences a child as these are often foods that are heavily advertised on television. An occasional fast food meal or hot dog is not going to be a problem if most of what she eats is nutritious. Some families have a relaxed meal once a week when pop and other junk food is allowed. Some prefer to have those foods even less often. Definitely introduce her to other foods, including those from other cultures, but don't be surprised if she isn't very adventurous yet.
Some children have to be exposed to a new taste up to a dozen times before they accept it.
If you prepare something new, make sure there is something available that you know she will eat. If a day care provider or babysitter is providing regular meals for her, find out what is typically served. Some child care centers have very nutritious foods, others are heavy on the salt and sugar. Begin talking with your child about your philosophy about foods. You can acknowledge that some things that taste really good are fine to have once in awhile but don't provide everything our bodies need to be healthy.