You could say "Hon vill gå till bion." but that would mean that she wants to go to the cinema building, whereas "Hon vill gå på bio." means that she wants to go and see a movie.
Is there something wrong with "she wants to go to the movie"? It rejected and replaced movie with "pictures"
It sounds like there's a specific movie she wants to see. As for the suggested answer, I don't agree with it, but apparently there's a dialect where pictures can refer to a movie theater.
I think it should accept 'she wants to go to the movies', which gets rejected. This would be the normal way to say this in English, 'the cinema' sounds arty and affected
Yes, teater only refers to the kind with a stage and live actors, never to movie theaters. It even makes me a bit sad that you use the word 'theater' for those in English. :/
Yes I guess it is just one of those things that English adopted with the modernization of the theater. I personally have only been to an actual "teater" once in my life so it is not surprising that the meaning became less important.
How come you don't need to say 'vill ha' here? Is it because the infinitive form of 'go' replaces the 'ha'?