@mimi0613 I'm asking this myself, if the family were going to the temple quicker then this would make way more sense - so I can only assume, that they returned quite early on the way, Eli excused herself the moment of home arrival, took secretly a quick horse and gallopped the whole way back - if we assume a way of a few miles and that the coachmen did need time to take away the horses and get the wood we see on the picture - they also are probably some servants of the sperados, not some assassins, so they would be quite reluctantly doing their work and the fire need a few minutes to spread
so let's say the carriage had a velocity of 4 mph, the way to the temple was 3 miles and they set the fire after two miles, they would need 45min for the distance and let's say another 15min for said things, sperado returned after 5 min of way, 5 min back, 10-15min for getting the horse, 10min to the temple (with 30mph in gallop), 10min for finding and telling knights, then the knights had about 15-20 min for going back and rescuing her - making the whole thing barely possible