J Simmons, as explained across several answers above, I would be confident that if you carefully review the plan provisions and maybe the beneficiary designation form, they will say that the spouse (i.e., #2) is the beneficiary for all of the account. The only other option is that the plan had a J&S and a QPSA for at least 50% of account, and that is almost never the case.
Of course, if spouse 1 or the children have a QDRO, that should trump.