If your sister has merely threatened to keep the other siblings out of the information loop and to ban you from visiting your mother, her threats are probably empty. Unless
there is evidence that you have physically or financially abused your mother, most nursing facilities will actively encourage visits and the free flow of information.
Occasionally, however, there can be a bad egg sibling who does truly act out of spite—and is good at convincing outsiders that his or her version of events is the only one.
In either case, you should voice your concerns to the nursing home administrators, who may even intervene or help set up a staggered visitation schedule to help avoid squabbles on the premises.
If you don’t get the help you need from the nursing home administrators, take the next step by contacting the nursing home’s ombudsman—a person outside the facility and not associated with the company who is responsible for investigating complaints, reporting allegations of elder abuse, and helping residents and family members solve problems through mediation. You can find local contacts and information through the National Long-Term Care Ombudsman Resource Center.