This article talks about Parental Alienation Syndrome. It only touches briefly on enmeshment,
but I still think you might find some useful info.

"One also has to look for factors in both the alienating and target parent to assess the potential for chronic alienation - the object of which is often to punish the parent perceived as responsible for the family demise by damaging his or her relationship with a child. Generally the parent who does not recover from hurt and anger over time will be already be vulnerable to narcissistic injury and predisposed to "externalising".or blaming. For the most part individuals who are thus predisposed will themselves have experienced significant deficits in their own parenting and/or have experienced significant previous losses that remain unresolved.

At times the enmeshment between the child and the parent derives in the parents sadness and distress and at others the parent's anger is too powerful a force for the child to resist"

Alienation Syndrome

Petunia