Responses
(1) well, in some games, potions doesn't really specify it's effects. Their descriptions are usually vague like Minecraft or Skyrim. It says that it can take this certain effect off of you or increase your health but it does not specify that inflicted injuries are healed.
(2) I also thought that our ML is OP but i think it's because magic is common among them. Let's say there are also 7 Billion people around their world, wouldn't you say that certainly with a lot of people out there, wouldn't there be a chance of them having holy powers?
There's a lot that doesn't sit with me the MC should know a lot more about this world in the mechanic even though this reality is similar to a game that she plays she should know how the magic system works when the maid was injured she should have known that a healing potion wouldn't help injuries and I think that the Merchant's son for a minor character is too op with holy powers