NC vs. Mask

Hey Guys. I got a quick question. I work HH and the Grandmother, who is in billing at a respiratory office, and is VERY VERY VERY OVERBEARING, stated to me this morning that she did not want a mask on her quad, averbal, g-button, severe head trauma granddaughter because an RT told her with masks, they do not breath right (something about to much CO2, she could not remember exactly why.).

I have always gone by the rule 1-4 lpm, nc, higher than 4, mask. To me a nc on 7 liters would blow away any nasal floor she has. I tried to contact RN, and of course did not get a call back yet. (and of course observe Dr. orders)
This is just a case of a nurse obtaining any knowledge that can be passed on from experience. Thank you.

Just to give you an idea of how overbearing she is, my pt is an 18 year old, fully deveolped woman, and the grandmother orders pedi masks for svn tx, even after my re-teaching her (almost 3 times now) that a pedi mask does not fit her face properly and she doesn't get the full benefit.) And there are several more incidents. I understand I must insure the family is comfortable, but this is trying on my nerves. The other day she insisted that Pt needed to be oral suctioned. I got everything ready (less than 10 sec), and there was NOTHING in pt oral cavity. Showed it to g-ma and she stated "well it took you so long to get the equipment, i guess she just swallowed it." I have been with pt for over 8 mos, and have never had to suction pt.)