Loosen The Apron Strings Meaning

(idiomatic, colloquial) To allow greater freedom (to someone); to relax control of (someone)

Example: 1948, Association for Supervision and Curriculum Development, National Education Association of the United States. Dept. of Supervision and Curriculum Development, “Educational leadership”, volume 6, page 534:
  They see how serious it is not to "loosen the apron strings"; how unfortunate it may be to talk about a child in his presence; how we must take people where...