Under §6428 and §6428A, the entitlement for Recovery Rebate Credit is with the taxpayer, not dependents.  The amount of credit, however, will increase for each qualifying children.

The COVID-Related Tax Relief Act of 2020 also amended §6428 to be consistent with §6428A, that mixed status families with only one spouse having an SSN valid for employment will still be entitled to the credit, albeit only for individuals with a valid SSN.

In other words, no credit will be computed on the return if neither spouse has a valid SSN, even if their qualifying children do.  The flip side of the coin is that if only one spouse has a valid SSN, the credit will be computed for that spouse and their qualifying children with valid SSN's.