but if anything were to go wrong
nicecupoftea has it IMO.
Many (most?) 14 year olds could survive just fine for a night or two. It’s not difficult.
The problem is what would happen if they or their sibling took a tumble down the stairs, took ill or somehow managed to lock themselves out etc. Fairly minor stuff that an adult would be able to deal with, but assuming that a kid would make the right decision in those circumstances, without the benefit of advice or experience to guide them, is risky.
If a neighbour or nearby relative is on hand, then not so much of an issue I suppose.
I should note that I accidentally set my garage on fire at 15 after my mum nipped round to my papa’s for an hour.