If a single use takes 5 minutes of her lifespan, a day would equivalent to 288 times it is used.
So, I think she can afford to use it a lot more than people think
Wasn't explosives are controlled by the government?
How come this pirate can just use it against a merchant ship?
Wouldn't you keep it for battle between battle ships instead?
My theory is MC has a named that control time. That's why she returned to the past.
Meanwhile, the sister has a power to increase the accumulation of malice. That's why the family hated her in the previous timeline. Also, since she accumulate malice, hessaros fought against the sister and broke...