No. TD status permits a spouse and unmarried children under twenty-one to accompany the TN professional and to study, but it does not authorize employment. A licensed practical nurse is not a listed USMCA profession; Registered Nurse is, and it requires a state or provincial nursing licence, so the spouse's own route depends on their actual credential.
Assess the spouse's credential on its own terms
The family question is really two separate cases. The TN professional's case is settled by the support relationship described above. The spouse's case starts from their credential: a practical-nursing diploma and Ontario RPN registration do not map onto the Registered Nurse entry, which requires a state or provincial licence as a registered nurse or a Licenciatura degree.
If the spouse intends to upgrade to RN standing, the sequence becomes: complete the education, obtain a licence, secure a prearranged US nursing offer, then apply for their own TN. Until then they hold TD, may enrol in a US program, and must not accept paid or unpaid work, including casual shifts at the same facility. Children may attend school in TD status.
Families who plan the spouse's upgrade timeline alongside the principal's three-year admission period avoid the situation where the spouse's licence arrives after the principal's status has lapsed.