Maybe the source material did it, but if the manga tried to explain the limits of her powers, or showed mc trying to experiment with what she could do, these feats wouldn't feel so out of the blue. Like the distance that she could make her potions appear, how far objects can be to enter the item box, what materials and size the potion bottles could be. If she could have a sword attached to a bottle, could she attach a house that she could live in? Make goods she could use to open a shop, like jewelry?