I agree she just needs a little attention. I would directly confront her, but nicely, sit her down, and say It seems that you are very unconfortable with the nursing staff, can you tell me what it is that has you so upset? Nine times out of ten it's just the stress of feeling helpless. Why not start suggesting she is such an excellent caregiver, she could probably care for him much better in her own home. As a retired HH nurse, I am shocked she didn't demand that. So, maybe she didn;t want to and feels guilty with her own decision?? Or wonders if the staff think badly of her for that?? Who knows??
As far as doing treatments, I can't answer for the rules of the facility, but in home care we instruct people do do all kinds of treatments, IVAB's, dressings, packing wounds, irrigating foleys, suctioning trachs, enteral feeds on pump and gravity or bolus, giving meds via enteral tubes, etc... So, frankly, if she was willing, and you could document a teaching session, and a return demo, I say, give her that. She wants some control, so put it in that her hands.
We have all been there, in HH I get the same way, Oh man, I have to go there again today??? Ugh!!!!! I find calling them on it is usually the best thing, sometimes all they need is someone to validate their feelings of helplessness, and other times they are a hopeless PIA!!