Probably closer to 50k after taxes, even in CA. The effective tax rate for a family of four at 60k federal with standard deductions, personal exemptions and child tax credits are around 5%, or 3k, or less at 60k.
In CA, after all taxes, they'd be lucky to clear 40k between them. I can assure you, thrown in all the other sky high costs in the state, counties etc, and that young couple working full time each, won't even be able to buy a home, and if they do, they'll be long distance commuting to where the homes are possibly more affordable. Then throw in even more more $$...At that income, they're screwed in CA.