Generate a touching scene with a visual narrative relevant to the question at hand. Depict a Caucasian, little girl with a longing expression, which conveys her desire for a new bicycle. Add an East Asian mother and a Black father in the backdrop, engaged in a conversation with serious expressions. Make sure the environment suggests a humble household with a few salvageable toys to emphasize the lack of new playthings. The bicycle is suggested to be absent from the image, signifying Sally doesn't have one. However, everyone should appear caring and respectful to each other.

Sally wants a new bicycle, but her mother and father will not buy her one. correct punctuation

The comma is correctly used in that sentence.

http://grammar.ccc.commnet.edu/grammar/commas.htm
See #2.

yes

"Sally wants a new bicycle, but her mother and father will not buy her one."

Sally wants a new bicycle, but her mother and father will not buy her one.

To correctly punctuate the sentence, you would add a period at the end:

"Sally wants a new bicycle, but her mother and father will not buy her one."