How does liability extend to the CNO?

Please help me with a response to this hypothetical case study. Any help would be greatly appreciated!

Mary Smith, CNO, has just been named in a lawsuit along with two of her registered nurses. The lawsuit arose as a result of a patient’s hip fracture sustained as a result of a fall. The two nurses named in the lawsuit were caring for the plaintiff on the day of the fall. Mary Smith, as CNO, claims that she had no involvement with the care that was provided to the patient and cannot fathom that she is also a named party on the claim. The lawsuit alleges negligence and seeks unspecified damages from all three nurses named. Discuss the following issues as they pertain to this case:

1. How does liability extend to the CNO?

2. What defenses are available to the CNO? In other words, what evidence can the CNO put forth to show that she should be dropped from the suit?

3. None of the nurses, including the CNO, have liability insurance. Is this a concern? Why or why not?