A spouse admitted in L-2 status is employment-authorised incident to that status and may work without applying separately for permission, subject to any professional licensing the occupation itself requires. Children admitted as dependants may attend school but may not work, and dependent status ends when a child turns twenty-one.
Each dependant has a different set of permissions
The spouse's position is comparatively generous. Employment authorisation flows from L-2 status itself, so the spouse does not need to find an employer willing to sponsor anything, and can take a job, change jobs or work part time. What that authorisation does not do is create a professional licence: a spouse who was a teacher, a nurse or a hygienist in Ontario still faces whatever the state requires before practising, and that process should start early because it is often slower than the immigration steps.
Children can enrol in school at any level. They cannot take paid work, including casual summer work, which regularly surprises households with older teenagers. Age is the condition to watch: dependent status is available only while a child is under twenty-one and unmarried, so a household with a nineteen-year-old should plan for a change to student status well before the birthday rather than in the month it arrives.