I’m pretty certain that it’s no legal standing at all, but I’m also pretty certain that she (the ex-executor) would try to assert that she has some.
Really the safest thing is for your girlfriend to consult a California-based estate attorney.
This is correct. I used to work for a bank and we drilled safety-deposit boxes fairly regularly. Generally because of lost keys, but occasionally because the renter died, the key couldn’t be located, and the estate executor requested the drilling.