Hmm... [No, they couldn't leave it to its own devices. Not unless they wanted it to make its way to the city, which is bad news bears for everyone involved.]

Well, stabbing at it certainly won't help. [She's seen what it did with that javelin.]

Perhaps a chemical reaction, or extreme temperature. Don't suppose you'd have anything like nitrogen up your sleeve, would you?

[Which is almost a joke, considering Pyrrha's attire. Rey herself could try flash burning, but she would have to get close enough.]