How should I help heal my sister's damaged nail matrix?

My sister suffers from a kind of OCD where she uncontrollably picks her skin and nails. Her thumb and index fingers have become so deformed that there is barely any nails left. Even at any sight of growth, my sister would pick it off because "it sticks out and annoys her". We brought her to the doctor and the doctor just told us to put bandaid on it and apply medicine and wait it out for 6 months.
Well i suspect there's a better method because after just 2 days, my sister took off the bandaid because it was wet and started picking at it again.

Part of her half moon have been ripped off.

I know what she needs the most is psychological support. This is tough because my parents are deeply religious (against psychology) and whatever I say don't hold much weight with them. But I'll continue to work towards getting psychological support for her.

but besides the mental aspect,

My main question is...

In terms of physical healing, what's the best way to handle this?

I read something along the lines of using dressing instead of bandaid, apply antibiotics daily, and not to be afraid of it being wet because it helps with healing contrary to popular opinion...

If you lovely nurse professionals can provide me with expert advice on what exactly to do, it would be very well appreciated. Also, I'm a complete novice in this... What kind of dressing should I purchase??
Quote from syphiaIf you lovely nurse professionals can provide me with expert advice on what exactly to do, it would be very well appreciated. Also, I'm a complete novice in this... What kind of dressing should I purchase??