They would advise to rewrite the sentence instead. The singular they appeared in the CMoS only in the 17th edition, and they approve this particular usage only

They would advise to rewrite the sentence instead. The singular they appeared in the CMoS only in the 17th edition, and they approve this particular usage only in informal speech: http://cmosshoptalk.com/2017/04/03/chicago-style-for-the-singular-they/ http://cmosshoptalk.com/2017/04/03/chicago-style-for-the-sin...