Children in their innocence seem to be drawn to St. Francis. The entire book is, also, on line and may be found here, among other places.
Most children love the story of the taming of the wolf of Gubbio, which is in the book.
CHAPTER XXXVI
HOW ST FRANCIS EXPLAINED TO BROTHER LEO A BEAUTIFUL VISION THAT HE HAD SEEN
St Francis being once grievously ill, Brother Leo, as he was in prayer by his bedside, was rapt in ecstasy, and carried in spirit to a great, wide and rapid river; and watching those who crossed it, he saw some brothers enter the river heavily laden, who were carried away by the current and were drowned; some contrived to reach one third of the way; others arrived as far as the middle of the stream; yet none could resist the rapidity of the waters, but fell down and were drowned. Presently he saw other brothers arrive; these carried nothing on their backs, but all bore upon the marks of holy poverty. They entered the river, and passed over to the other side without any danger to themselves. Having seen this, Brother Leo came to himself; and St Francis knowing in spirit that he had had a vision, called him to him, and asked what he had seen. When Brother Leo had related to him the vision, St Francis said: "What thou hast seen is indeed true. The great river is the world; the brothers who were drowned are those who do not follow their evangelical profession, or practice the great virtue of poverty; but they who passed the river are those who neither seek nor possess in this world any earthly riches, who having food and raiment are therewith content, and follow Christ naked on the cross, bearing joyfully and willingly his sweet and easy yoke and loving holy obedience: these pass easily from this earthly life to life eternal."