I was thinking here, what if Leah discovered some ring or talisman that gave her magic, like lightning or fire magic, and more, and if to explore certain areas she needed certain items to access this area, like a pickaxe made of insects or something like that
We already have the magic book that unlocks a the Fire ball and Healing spells, more spells require balancing with the current actions.
Locking areas behind requirements could be interesting, and I think we may end up with something like, find a key or a way to access wherever, which is common in point and click style games :P.