I understand you not wanting to be a PITA, because of fear of retaliation. I don't mean physical retaliation but I have heard more than one colleague say how they walk just a little slower or put them at the bottom of the list for meds when people speak up. My advice is document everything--time she called for med, time it came, nurse who brought it. Go up the chain of command if need be, let them know you understand the scope of their work and the overwhelming volume but you are there to support your mom and if that means being a PITA then so be it.