Yes, in practical terms. An L-2 spouse is employment-authorized incident to status, so freelance translation for Québec clients from a U.S. address is permitted, subject to tax and business-registration questions that are separate from immigration.
L-2 work authorization covers self-employment too
Hypothetical example: the senior builder's wife is a freelance translator who serves law firms and manufacturers in the Québec region from home. Unlike TD spouses, who may not work, L-2 spouses are employment-authorized as a consequence of their status, and that authorization is not limited to employment by a U.S. company; she may continue her own practice.
What changes is the administrative context: her business would be operating from a U.S. location for tax purposes, her Québec professional-order membership may have residency conditions, and her clients may need to know she is invoicing from abroad. Those are questions for an accountant and her order, not immigration obstacles.
Her L-2 status is tied to his L-1B, so the five-year ceiling and any change in his employment affect her too. Any children may study in L-2 status but may not work, and they lose derivative status at 21.