Isn't there a requirement that there be some criminal activity to be legally extortion? So if she was threatening to tell the IRS about the firm's tax evasion,

Isn't there a requirement that there be some criminal activity to be legally extortion? So if she was threatening to tell the IRS about the firm's tax evasion, that'd be illegal. Otherwise it's just everyday negotiation and settlement, right? How would you draw the line? E.g., "You've been using N more Windows licenses than you paid for. Pay $M or we'll sue for payment."