Yes, if the U.S. subsidiary keeps control of her work and the placement is for its own product or service rather than to supply labour to the customer. The length is not the issue; the control and purpose are.
Offsite work is judged by who directs it and why
The rule prohibits placing an L-1B worker at an unaffiliated site primarily as labour for hire under the customer’s control. A placement passes when the specialist is there to deliver the petitioner’s own product or service using its specialized knowledge, and when the petitioner continues to assign, supervise and evaluate her. The services agreement should therefore describe a licensed process being implemented, with milestones the subsidiary owns, and a named subsidiary manager who supervises her, including through site visits and reporting.
It should not describe her as filling a vacancy in the customer’s quality department. Alongside the offsite question, the ordinary L-1B elements remain: she must have specialized knowledge of the company’s processes, a continuous year of employment with the Canadian company within the last three years, and the two companies must be related and active. The petition should address each of those separately rather than assuming the customer relationship carries them.
A first review produces a control map naming task assignment, leave clearance, performance review, and removal authority at a customer site. Hypothetical example: a bioplastic-extrusion company sends its polymer-formulation specialist to calibrate a customer’s line. The service agreement and reporting records should show that the petitioner directs the specialist and owns the deliverable.
A customer shift schedule that treats her as replacement labour points the other way.