I think you can only deal with what is in front of you.

For all we know, this child developed the behaviour after the last boyfriend left. That she is 11, with all the other factors discussed, the development of this little girl could still be a matter of change to what was.

And, unless this woman has, herself, some need to nurture this behaviour, rather than to put up with it to keep the peace, she could be thinking this is a 'phase'. I find it would be difficult to consider that the mother doesn't realize that she's doing more harm than good, by allowing the behaviour. Regardless of her own needs.

And, it all really boils down to who's needs are being met. We don't know why the little girl insists on being joined at the hip to the mother, and we don't know why the mother allows it- but does she encourage it? Or is it a matter of giving in, and not being able/willing/skilled enough, to straighten their relationship out.

But, I don't hear you saying that the mother feels the need, or expresses a need, to change. If she does, I've missed it. Does the grown son talk to you about this? Do you have any historical information as to when it started, and has he talked to his mother about it? How does he see things, and what are his plans- college, working, getting his own place.

If you are dealing with a situation (that I think you see accurately), that has potential to change, nothing will happen unless you push the envelope a bit. This is your life too. What if she tells you she sees nothing wrong, and expects you to just accept things the way they are. Can you?

I would be careful not to jump to any conclusions without first getting into couples counselling to address the issues that need to be addressed. And to do that, she needs to be willing.

I have the feeling that there is much more to this.