Yes, because her client answered the question truthfully. The press and the public are outraged about a hit and run driver who hit a child and sped away from the accident. Police attempts to locate the driver have been unsuccessful. With his permission, she starts plea bargaining with the prosecutor. She complies with his demand that his identity not be disclosed.
Word leaks to the press.
The parents bring a civil lawsuit against John Doe. They schedule a deposition and intend to make her disclose the identity. She must disclose because a crime has been committed. She may disclose because a crime has been committed. She must disclose because the identity of a client is not protected information.