Not on the basis of the pending petition. Until conditional permanent residence is obtained, neither spouse has work authorization from EB-5, and work in the United States before then requires a separate status. After residence, both may work without restriction.
The petition grants nothing until residence begins
Filing Form I-526 confers no status or work authorization. If the couple are in Canada while it is pending, they wait for approval and visa availability, then complete consular processing and enter as conditional permanent residents, at which point both spouses may work for the company or anyone else and the children may study. If instead they want to be in the United States managing the start-up during the pendency, they need a nonimmigrant status that permits it, and the choice interacts with EB-5.
E-2 is possible for Canadian citizens whose investment in the same enterprise meets the E-2 tests, with the spouse work-authorized incident to status, but intent questions alongside an immigrant petition need careful handling. Concurrent filing of adjustment with the I-526 is available only to investors already lawfully in the United States in an eligible status. Children's ages for derivative purposes are measured under the Child Status Protection Act, so a Paradise family with a child near 21 should plan the filing date with that calculation in hand.