Her name appears in at least half the companies in question (that I recall). They’ve picked through all these financial reports going back years with a flea comb. If they can prove wrongdoing, then they’ll charge her sooner or later.
The plea agreement always references to “and others” or “co-conspirators”.
Example from his agreement (defendant is Taieb):
Defendant, Vaccaro, Svorai, and others, sold, at a discount, large blocks of shares in the Manipulated Public Companies to co-conspirators who were aware the stock was manipulated in order for the co-conspirators to profit when the stocks were promoted and for the Defendants to receive payment for the shares upfront.