Harden the target should come first.
But there's a necessary precondition to your mom getting a gun for self defense: has she decided she could actually use it against another human being?
If she says 'yes', then you should take her at her word.
Rather than a handgun, she and you might consider a side-by-side coach gun in 20 gauge - one example - http://www.stoegerindustries.com/fir...coach-guns.php
, Magazine Qs
, Knife laws
Unless there is some way to amend a bill so you would support it,
the details do not matter
until the Governor signs or allows the bill to become law.
Ask CA law questions in the How CA Laws Apply to/Affect Me Forum
- most questions that start 'Is it legal ...' go there.
Not a lawyer, just Some Guy On The Interwebs.