One sheet per paper: every question reprinted, the answer, the method, and the mistake to watch for.
These are for the grown-up, not for her. Nothing stops her opening them — the site has no passwords — so the useful discipline is to open a key after she has committed to an answer, never beside her while she works.
Some of these papers print no answer key at all. Those answers were worked out here, which means they can be wrong — so every question on every sheet is tagged official answer or derived — check the method, and the method is printed so it can be argued with.