I can only comment on this as a not/never have been a JW. I am divorced, have 2 adult children, have brothers and sisters.
As far as my son and daughter are concerned, nothing but nothing would interfere with my unconditional love for them. Although I now live 2000 miles from them and the rest of my family, one phone call would have me on the next plane and doing what I could. If I turned up at the doorstep of any of my family, or of a close friend, I know I would be welcomed, could stay as long as I liked, etc. They know the same.
That is also true of my ex. (Well, not entirely,'cos her current boyfriend wouldn't be too pleased). But if she or I needed help, we would be there for each other. This has been tested in the past and is true.
'Shunning' or whatever name you want to call it is not natural, is not loving, and my personal view is that if us 'worldly' people can achieve more or less unconditional love the fact that 'loving Christian' peple can't is an indictment on them.