if my two kids chose to go NC with me, the first thing I would do is examine my own behaviours and figure out how to set things right. I would feel really invalidated if my husband kept trying to help my parents.
Flight safety instructions advise, in the event of an emergency, to put your own oxygen mask on first, before attempting to help others. If you see someone struggling in the water, of course you'll want to help them. But what if you're not a strong swimmer? What if you get out there and try to help them, but in their panic, they are fighting your attempts to help, and causing you to be in danger of drowning?