Yes, although I always find it a bit puzzling when people on here declare their young children 'sensible'. Young children (up to about 8/9, I guess) aren't 'sensible' per definitionem, and it's always wise to expect the unexpected. That said, a typical 13yo should be able to deal with most scenarios potentially presented by a typical 6yo, so it's fine. I've left my 4yo with my ('sensible') 14yo for a similar amount of time.