@dethdukk
Huh, doesn't the Book of Life require the sim that will be rejuvenated to be killed off first, which is particularly difficult with children, since they can only be killed by fire?
(And also it needs to be bound to the sim before it dies; killing it off and then trying to write, or bind, the book does not work.)
I do use that tactic with adult sims and the cowplant, mind you. I just don't think it very feasible for children.