Re: doctor's right and patient's right versus nurse's rights...
In nursing (as in life) there is a big difference in being assertive and aggressive. A good nurse is assertive - she stands up for her rights and those of her patients in a respectful manner. An aggressive nurse is not a good thing...this is a person who is difficult to work with. In my practice I have refused to give a med, requested a med, advocated for certain things, and asked family/visitors to leave. Always in a respectful but firm manner.
I work in the ER, and have decided that I have certain rights.....to be safe (this is #1 to me and I don't hesitate to make that a certain thing). I also feel that the care of my patient comes next. If this means kicking out visitors that are being disruptive, or just asking them to leave for a procedure, I will do it. I have walked out of the room of a pt room being disrespectful (of course, did my ABCs first.....pt yelling, definite airway and breathing, skin PWD).
I'm sure your mom is a nice person, but even people with "strong personalities" need to tone it down at work, and keep their priorities straight.