As professionals, of either sex, it is incumbent upon them to not only represent the firm and bring in money from clients, but to represent themselves to the firm to justify higher pay levels.  
Private businesses are not charities, their goal is to make as much money as possible, and if high-talented staff are willing to work at a relatively lower levels of pay (my guess is that relatively low is multiples of $100,000 for a big law firm) then so be it.
Both John Tory and Kevin O'Leary have stated that if a female executive feels under paid and can prove that they are profitable to the company, then they have every right to bring that up with senior management.  Tory stated that men are far more likely to make the case for pay raises than women and O'Leary stated that the most profitable companies he owns are run by women and he will pay them accordingly.