"The girl is wishing for a horse."
Translation:Pigen ønsker sig en hest.
I'm gonna continue the line of unanswered questions, by asking if the "sig" is necessary? Is "at ønske" a reflexive verb, or is the "sig" there to clarify that she wants the horse for herself? If the latter, seeing as the English sentence does not explicitly specify who she wants the horse for, can the Danish sentence be written without it?
That is because this is a reflexive verb. Some verbs are reflexive meaning that they must refer back to the subject. I believe you just have to learn the cases in which this is required. If you are really trying to learn the language - check out some children's comics from denmark (ie Rasmus Klump) You'll see a lot of simple sentence structure that helps you learn when and where to use reflexives