Yes. L-2 spouses are employment-authorized incident to status. State occupational licensing is the separate obstacle, and for regulated roles it can take longer to resolve than the petition itself.
Status permits it; the licensing board decides when
Hypothetical example: the fabricator's wife is an early-childhood educator in Grand Bay-Westfield and expects to look for a centre position after they arrive. Her L-2 status authorizes employment without a separate grant, so the immigration side is straightforward. The licensing side is not automatic: states set their own credential, coursework, background-check and sometimes residency requirements for licensed childcare staff, and a New Brunswick qualification may need evaluation or supplementary courses.
She should identify the specific state agency, ask what a foreign-trained applicant must file, and start it while the petition is pending rather than after arrival. It is also worth checking whether the eighteen-month assignment length makes a full licensure path worthwhile, or whether an assistant role that does not require the licence is the better use of the time.