I agree. That time is the day the child moves out, before which time they are not "full grown" adults IMO. Close maybe, at most
A full grown consenting adult is that by law not when they move out of the house. There are 15/16/17 yr olds that are moved out of the house, they are no more consenting than a 4 yr old- legally-Unless their states law books state so.
There are adults living at home- again for various reason- some even pay their parents rent in a landlady/lord situation. They are adults even if their address is the same as their parents. While they do need to respect the wishes of their parents, they also have full right to live their life.