TD status does not authorize employment, including work performed from a US home for a foreign payer. A separate qualifying authorization would need assessment.
Separate location from the payment account
Write down where the spouse would physically work, the proposed duties and existing status. Do not assume Canadian billing makes US work permissible. A spouse and unmarried children under 21 may qualify for TD subject to the requirements; dependent eligibility does not create work permission.
If the spouse intends to keep working remotely, including for an employer or family business based in the region, record that explicitly rather than assuming rural residence changes the analysis. Gather marriage and birth records, passports, and prior immigration documents, and avoid making the principal's employment letter carry facts that belong in a dependent's record. If the added income or schedule change affects household planning, such as childcare or a spouse's own work arrangements, discuss that separately from the immigration authorization questions, since the two issues have different evidence and different decision points. The principal must independently show citizenship of Canada or Mexico, an occupation named by USMCA with its required credentials, and prearranged US employment rather than self-employment; Canadian permanent residence alone is insufficient.