In the tips, tricks & notes section of this quest guideline it says that the jump across the gap in the pyramid cannot be made if you weigh more than 42 or 43 kg, however I was able to jump over it a few times while weighing 53 kg. Also, it should be noted that if you have less than 20% of run energy you won't even be allowed to attempt to jump across the gap. Another helpful note for this quest is that after it has been completed the carpenter will buy willow logs off you for 40gp each, as well as buckets of sap for 30gp each. [pokemama note: my sis couldn't succeed at the jump unless she had at least 80% energy. not sure at all why that was, her agility is quite low tho.]