Since both CA and NM are community-property states, I hope they have a prenuptial that declares they are waiving community-property laws assigning income.  Otherwise all of the California income and half the New Mexico income will be taxed to California, with a credit for some of the tax paid to New Mexico; and all of the New Mexico income and half the California income will be taxed to New Mexico, with some sort of credit allowed there also.  Glad they're your clients and not mine.