Wall Footing

I had a gate wall (slump stone) that was 16" wide on one side and 38" wide on the other. We demoed it and want to make it 32" on each side with a gate in the middle. Can I use the old footing? The side that is 16" wide only has an 18" footing. Can I just extend it? and dowel in some rebar or is it a much better solution to just demo the footings and repour everything. the wall will be about 60" tall. I live in CA.

thanks