I know someone with a probation violation who now has a warrant. They don't have the money to go through the legal process right now so what states can they be safe from being extradited from until they can get the money to resolve the problem?

Florida has no choice if California chooses to. They have the right to if they want to.
And there is no real legal process since extradition is almost automatic within states. All they have to do is be willing to pay the transportation costs.

But what will happen if you are stopped you will be held pending California deciding if they are going to or not.

And you can be stopped and held every time they stop you since the warrant always stays open.

So there is no for sure answer, if the felony was not overly serious and what was the violation ? It all matters, and also did your case make any news headlines, that puts pressure on bringing you back,

Was there a victim of the original felony that may be putting pressure on a DA

Is it a election year for the DA or judge to make them want to "get tough on crime"

Or even somewhat more funny and I have seen this happen, you get stopped in the middle of the night and some low level person in charge that night has to make the judgement call, and so on.

So can they yes, will they in my opinion, no, but it can happen.