In our family my husband stays home with our boys. As the paid (originally said 'working', but both work!) parent, I say make sure you get a pass for the spouse. Figure out how many times that person will have to go for the pass to pay for itself, and ask him/her to PLAN to take maybe 1 day off from work/month (or so) to go with the family.
Here's why: I can't tell you how often we'd have someone from out of town want to go, or other friends with passes want to take Friday evening to go on a few rides with their kids too. If I hadn't had a pass either I would have had to stay home or we'd have had to pay for it. Totally worth it.
Make sure you get the park-hopping passes, too. CA adventure has A LOT of kid-worthy stuff -- much that you don't have to wait in line for. On sunny days, bring a change of clothing because there are places to play in the water.
And pay the extra $$ to get the parking included for the SAH parent's ticket. This made it much cheaper in the long run.
Enjoy!