I'm not aware of any evidence that Ana knew at the time of the sale that the artworks were forgeries and not the originals he took from South Korea.I'm late to this, but just watched Lawyer Lee's excellent recap of the art fraud part of this case. I recommend.
Her review makes me wonder how Anna could not have known about the art fraud and the money. Her accounts were used to try to sell the Warhol forgeries. How could she not have known?
If she knew, she may have been complicit. Why escape to Washington DC? Just for the job? I wonder if she was planning to escape Brian with a lover Fastow, hopefully extract herself from the legal situation in Massachusetts, perhaps even with a delusion that she'd be able to access the money or the originals. Did Anna know where the original Warhols were? And, was that a reason Brian wanted to kill her? Still, nobody knows where the originals are, except Brian.
He could have sold the originals before he and Ana were married. One lot of forgeries were painted from photographs, according to Lee.