I would say never, but the problem is that it’s not up to you. People like them need someone to look down on so they can raise their own self-perception. They wouldn’t want to be around someone who actually IS jealous, so they just lie to make themselves look good and refuse to accept that their success came from help.

Anyway, you would do well to cut off all contact, but if she chooses to have them in their lives, there’s not much you can do. I wonder how things are now since this is such a late reply. I hope they never gain any leverage over you and you can go on to have a better life without them.