First thing: when and where did she use her EBT card (county benefits).
I work at a welfare agency in a CA county, but it's quite decentralized; each county is given autonomy to implement administration of public benefits.
i believe that EBT cards become inactive after some 180 days of no use. They can be used across CA counties and even in different states.
Food stamp eligbility must be established every six months, so the case would have closed within six months, but even if the case is closed, the benefits remain there until they get expunged (but they can be re-activated).
There's a toll free number to reset the PIN, if she had lost it. Getting a new EBT card is trickier; it's possible to reissue an EBT card from another county, but it's quite difficult and may not always work.
Sorry for rambling off a bit, the priority is to find out where and when her EBT card was last used.