These young ladies--not supposed to have been actually christened by the names applied to them, though always so called in the family from the places of their birth in barracks--are respectively employed on three-legged stools, the younger (some five or six years old) in learning her letters out of a penny primer, the elder (eight or nine perhaps) in teaching her and sewing with great assiduity. 
These young ladies - not actually christened by these names, though always so called, from the places of their birth in barracks - are sitting on stools, the younger (five or six years old) learning her letters out of a penny primer, the elder (eight or nine) teaching her and sewing. 