No. TD allows study but does not authorize employment, so a spouse cannot take design work, freelance commissions or unpaid professional work while in the United States on TD. Continuing to serve Canadian clients remotely from the United States is also not authorized.
Plan the spouse's practice before the move
Design households often assume a spouse can keep a small client base going. Because that work would be performed in the United States, it needs its own authorization. Raise it with counsel before commitments are made to existing clients, and consider what a period without professional practice would mean for the spouse's own licensure or continuing-education requirements at home.
Hypothetical example: the applicant's spouse is a horticulturist who supplies planting plans to two Canadian nurseries and expects to keep both accounts. Performing that work from a United States address is employment in the United States whatever the client's location or the currency of the invoice, so TD does not cover it. Two practical questions follow.
The first is whether the spouse has an independent basis of their own worth assessing, which is separate from the principal's route and carries its own conditions. The second is what the spouse tells those clients now rather than after the move, since a designer who goes quiet mid-season without notice generally loses the account for good. Settle both before a start date is given to anyone.