When does a divorce in CA become final?
Kinda depends on what you mean by "become final," but one answer would be when the court enters a judgment of dissolution and the time to appeal the judgment has expired. Note that I'm not sure what this question has to do with the rest of your post.
My ex wife is collecting spousal support and has been since 2019. She is now asking for additional money even after taking half of my retirement.
I assume "taking half of your retirement" means that the court ruled, as part of the division of community property, that she was entitled to 50% of the value of some sort of pension plan or IRA or some other similar asset. Correct? Note that the division of community property is a separate issue from support obligations.
When you say that she is "now asking for additional money," what exactly does that mean? Is she asking that the spousal support obligation be increased? Has she filed a petition for an increase? If so, on what basis is she seeking the increase?
I do not understand how she can continue to ask for additional money even if she refuses to work.
I'm not sure what's difficult to understand. Anyone can
ask anyone for anything. Just because someone asks for something doesn't mean he/she is entitled to it. If you want an assessment of your ex's likelihood of getting the spousal support obligation increased (if, in fact, that's what she's seeking), you'll need to start by answering the questions I asked.