"La ragazza aspetta fino a cena."
"The girl waits until at dinner"... seems to be the direct translation. Why is 'a' in there?
"fino a" is a form of prepositional phrase (locuzione preposizionale)
- check this link http://grammatica-italiana.dossier.net/grammatica-italiana-12.htm under Locuzioni prepositive -- gruppi preposizionali for other examples.
To say "until at dinner" is redundant. The word "until" already incorporates the literal meaning "[temporally] up to dinner." Thus, to say "until at dinner" is akin to saying, "up to at dinner [time]." Does that help? (:
That would be "la ragazza aspetta la cena"; "fino a" means until or up to, so the girl is waiting until dinner is served.