A legally married spouse in E-2 status is employment-authorized incident to that status and may work for any employer or run a business. Unmarried children under twenty-one accompany and may attend school without work authorization. Nothing in the classification leads to permanent residence for any of them.
Good working rights, no permanent destination
The spousal position is generous and often decides which route a household prefers, because it removes the wait that a separate work permission would create. Set against that is the structural limit. E-2 status can be renewed while the enterprise continues to qualify, and families sometimes spend many years in it, but it grants no direct path to permanent residence, and a household that treats renewals as a slow route to a green card has misread the classification.
Children are the sharpest edge. A child accompanies only while unmarried and under twenty-one, so a nine-year-old today is a planning problem in twelve years, and a nineteen-year-old is a planning problem now. Families in that position usually look at whether the young adult has an independent basis, at a student route, or at whether an immigrant category should be started by somebody in the family long before the birthday arrives.
Each person's own activity, age and citizenship decides their position.