I agree that nobody needs to know. One other thing that I would make damn sure of, would be to make a visit to the hospital where your mom is being treated and have them REMOVE any reference to her being a JW from her computerized record.
HLC members have been known to use their position to perform what the hospital regards as Pastoral Care Visits. They can request a list of all JW patients in the hospital and will make unannounced visits, wearing hospital approved ID, to patients on the JW list.
They can also gain access to the patient's chart under the guise of documenting a pastoral care visit. Make sure that the hospital staff is aware of your concerns and does not permit Pastoral Visits without your consent. In fact, the best way to keep them out is to request a CONFIDENTIAL PATIENT code on the patient's computerized record. That way, only the people who have been authorized by the patient can contact by phone or make visits to the patient.
To the hospital and most nursing staff, the Pastoral Care Visit appears to be an innocuous, supportive supplement to the medical care the patient is receiving. However, in the case of JWs, we all know that the HLC's motive is more about ensuring compliance with WTS directives than it is about offering support to a patient who is struggling with serious illness.