beneficiary on structured settlement annuity

I'm not a California attorney, and the law can vary from one state to another, but I doubt that this other person will get anywhere.  In most states, there are two things that are true about the annuity:  first, it is a contract set up in a way that it describes exactly who gets what money and when, and that is designed to be effective outside of probate (meaning will, no will, it doesn't make a difference);  second, the beneficiaries on that annuity, and their different interests, have been specifically approved by the person who won the settlement and her lawyers, and quite possibly by the court as well.

A stranger to all of that is going to have a very difficult time, I'd think, getting their hands on any of the money.  They would definitely have to go to court to try this.