If she is dealing in that amount of money then she had to report it on her 4th quarter reporting Sept. 15. If it was savings, she had to fill out documents at the bank. You cannot deposit or withdraw large amounts of cash without reporting it. If she did it in small amounts to avoid reporting, she will go to jail just like Hastert did. That is called "structuring" and it is illegal. Even a bank and its employees can get in big trouble for not reporting it. $250,000 is a LOT of cash. That would have required a BUNCH of reports if it ever went in and out of a bank. It would have required one HEFTY quarterly tax payment if it was just income.
If she sold her own property to acquire that cash and so it was money reported years earlier, well....then she will have to account for who bought the items in order to prove it. This is not a $25,000 car sale. This is a quarter of a million dollars in cash riding around in the back of her car. There was no search until the skilled dogs alerted them to probably cause. Totally legal.
4th quarter ends in December. Reporting earnings a quarter ahead of time requires prescience, and while that isn't past the IRS to do, it isn't realistic. So far, they have only penalized people for not knowing they were going to have a better fourth quarter than they had anticipated, as far as I know.
As for accumulating money, I have a tin box (.30 caliber ammo can, actually), where i dump all the change in my pockets at the end of the day, and have done so for years. It is the second such box I have, and the full one just sits where it may be a coin hoard for the great grandkids some day if I don't need the change before then. But if I were to transport this, and the dogs hit on the residues from it being an ammo can and all, would it get stolen from me as ripped off parking meters or something? Maybe part of a lunch money rackett in grade school? I'm sure someone could invent some crime the money is guilty of, regardless of how farfetched it may be, in order to take it.
I can see freezing assets until their provenance can be determined, and restoring them promptly to the owners in the event no crime can be proven. I cannot agree with taking those assets and requiring the owner to sue for their return (another loss on the owner) with no charges filed, no burden of proof, no due process. And I don't consider passing some law that says if you have more than the officer thought you should have (whatever that means) they can just take it to be due process.
When we reduce our 'law enforcement' folks to highwaymen, who will guard the rights of the citizens.
That question was answered at Bannack, MT, years ago. It ain't pretty.