What is "to be in leading strings"

Leading \Lead"ing\, a. Guiding; directing; controlling; foremost; as, a leading motive; a leading man; a leading example. -- Lead"ing*ly, adv.

Leading case (Law), a reported decision which has come to be regarded as settling the law of the question involved.
--Abbott.

Leading motive [a translation of G. leitmotif] (Mus.), a guiding theme; in the musical drama of Wagner, a marked melodic phrase or short passage which always accompanies the reappearance of a certain person, situation, abstract idea, or allusion in the course of the play; a sort of musical label. Also called leitmotif or leitmotiv.

Leading note (Mus.), the seventh note or tone in the ascending major scale; the sensible note.

Leading question, a question so framed as to guide the person questioned in making his reply.

Leading strings, strings by which children are supported when beginning to walk.

To be in leading strings, to be in a state of infancy or dependence, or under the guidance of others.

Leading wheel, a wheel situated before the driving wheels of a locomotive engine.