We are the primary caregiver for 2.5 years of my mother-in-law (she is 94). She lives in Assisted Living and we see her every day. My brother-in-law lives in China and sees her 3-4 times a year. He is constantly threatening us with lawsuits because he doesn't like a doctor or medication she is on or methods of care we are providing. He thinks we are trying to kill her. She is in seriously poor health and may pass soon. He is also threatening to sue her doctors. Do we have anything to worry about?