The commercial build-out can proceed, and doing so strengthens the file, provided Marta is not performing the work of running the business in the United States before she is authorized.
Commit the money, defer the personal labour
Signing the lease, ordering equipment, arranging utilities and licensing, engaging a local manager and hiring staff all constitute irrevocable commitment and make the application stronger rather than weaker. None of that requires her to be present working. What must wait is her own participation in operating the enterprise on site. Many investors bridge the period by engaging a manager, which is also useful evidence that the business is real and operating. Trips to inspect premises, negotiate and sign documents are a different matter from working, but the distinction should be understood before travelling rather than explained afterwards at a port of entry. Keeping a written record of the purpose of each trip is a sensible precaution while the application is pending.
Hypothetical example: A Canadian buyer signs a conditional agreement for a United States bicycle-repair shop that has a fixed closing date. The first review should map the deposit, lease, licence applications, seller transition, and the investor’s proposed first day of operational work. The purchase agreement settles which funds are exposed and when. If the seller will not accept a condition that protects the buyer while the application is pending, closing first creates a commercial risk that should be understood rather than disguised as an immigration shortcut.