I think that one way in which this forum may be helping a great deal is to allow us to reveal our shame to a caring and supportive community of grandmothers who are enabling it to fade. We can see more clearly, from the feedback that we receive ourselves and from reading what others write, that it is highly improbable that we deserve to feel ashamed. The emotion doesn't fit the facts of our attitudes and behaviour when viewed through a wide lens.
Some of those who are estranging us may themselves feel ashamed and may be resorting to using shame as a tactic to reduce (project) their own shame as well as to try to motivate us to change. They may not be entirely aware of doing so. Aware or not, I think that the message needs to be imparted - through a softly, softly approach or more directly - that this is an unsuccessful ploy and that it is better to try to re-engage and work with us on what may be a long, gradual, uneven and at times difficult process of cultivating a better relationship. They - and we - will need to reach a stage of feeling strong and brave enough to be able to listen and talk to each other and to be able to tolerate distressing thoughts, memories and feelings which are likely to surface.
The thing about shame is that it makes us want to avoid contact, though, doesn't it?
If we think that the person estranging us may be masking shame, and there is an opportunity or way in to make some sort of connection with this person, perhaps we can try exploring gently - just a tiny bit - what troubling thoughts the person may have. But how to start off? Aye, that's the rub. Could it be brought up in an almost casual way? Can it be "normalized"?
If in time it becomes less of a big deal for the person to talk with us, and open up more, we might come to learn, for example, despite appearances to the contrary, that (s)he considers her/himself to be a bad person underneath or an inadequate parent or a failure as a friend or at work or a pretty rubbish partner etc. or that (s)he believes that there is something else that is very wrong with her/himself or that (s)he feels out of control because of certain feelings and impulses. (S)he may be giving her/himself a very hard time over something that happened in the past e.g. blame self for being abused, molested or bullied long ago or because of her/his parents' troubles or for something else that happened and be struggling because of self-blame, self-disgust and self-criticism as well as the fear of being ridiculed, rejected or condemned if these things are spoken of.
If these conversations continue, with anyone who can provide a sense of containment and safety, in time (s)he may discover that (s)he is not rejected, reviled, despised etc. and can stop giving her/himself such a hard time.