Family Harassment

I work at a Skilled Nursing Facility (a care center), where my grandmother stays. Everything has been good until my aunts (my mother's sisters) started complaining about me caring for my grandmother, mainly about how relatives shouldn't care for other relatives and how unethical it was. My mom has PoA (Medical and Financial), and my boss has never questioned/doubted that the care I provide was professional or that I was being unethical. It has effected my job because I work on night shift and there is only two CNAs there (myself and one other), and when we do rounds (checking on people and changing clothes) she is a 2-person change (requires one of us to roll and the other to change). Is there anything I can do to prevent them from causing problems or am I actually doing something wrong? Not sure quite if it goes in here, but it seemed more fitting than the other choices. Yes, I asked her PoA if I could write this and state some facts.