Is there a free grave in California for an elderly on general assistance?

Cremations are cheaper than burials.
Contact your local hospital and ask for the social worker for hospice. She had a list of places and prices for burial and cremation.
I'm sorry for your loss and this situation.

The federal government provides a burial death benefit:
"1. Lump Sum Social Security Death Benefit. A spouse (who is living in the same household) can receive a one-time lump sum benefit of $255. ... If the Social Security death benefit is being paid to an eligible dependent child, then an application must be filed within two years of the insured worker's death.Aug 8, 2017"

I thought I posted to this. If parent is a Vet he maybe able to be buried in VA cementary. On the local level the plot and and stone (actually plaque) are paid by the VA you will have to pay for the opening. Your county VA can help u or the funeral home. On the National level, u need to be cremated and you pay for nothing.

I'm sorry, but at a state-funding level, California does not provide burial or funeral assistance. You may want to contact your county's social services department to inquire what services they're able to provide and the eligibility requirements. There's usually a general relief budget within the county or city to cover basic burial or cremation costs for those on welfare and without funds to pay for a burial.

Contact the social services office where your loved one resided and hopefully, they'll be able to tell you what the county/city can assist with and how one qualifies.

Best wishes.