To be honest everyone is winging It and doing their best . Most caregivers are Isolated with no Support that's why so many Of us are Burnt Out . Keep asking for advice on this forum and face book has support groups also .
If you are POA you have to act in the best interest of the parent . But that does not mean you have to be the one to do the hands on caregiving or live with them .
Without POA you have no power .
A more detailed question may help get you better answers .
Caregivers should stay within their 'scope of practice' eg keep to caregiving tasks within their training & experience.
Is there a specific duty that needs doing or is causing a problem?
Or is this regarding actual legal issues eg Handlng money, signing or witnessing documents?
Marry their client??
Without POA you have no power .
A more detailed question may help get you better answers .