Yes. Derivative TD status permits residence and study, so children may enrol in school and a spouse may study as well. What TD does not permit is employment of any kind, including remote work for a Canadian employer performed from inside the United States, and derivative eligibility ends at twenty-one.
Study yes, work no, and watch the birthdays
For a household moving on a school-year timetable this is usually good news, since the children's position is the simplest part of the plan. Enrolment itself is a school district question with its own residency and records requirements, separate from immigration status, and it is worth asking about early because districts differ. The harder constraint sits with the spouse.
TD carries no work authorization at any point, so a partner who intends to keep earning needs an independent status that permits it, and the relationship must be a legally recognized marriage because a common-law partner has no derivative eligibility at all. Age is the other fixed line: derivative status ends at twenty-one regardless of how much of the principal's period remains, so a household with an older teenager should map that date now. Where a second income is essential, the L-2 and E-2 spouse rules are worth comparing, since authorization comes with the status there.