Confusing situation need help

[understandnow]

My son is married with three children and a daughter from a previous relationship.  The first daughter is 11 and the oldest. He was not involved in her life for the first 8 yrs of her life.  My husband and I have been there since day 1 and she lived with us for a short while while the mom was getting her life in order.  We coparented her with her mom for the first 8 yrs of her life and she celebrated every holiday and weekends with us.  She is very close to us to this day.  The problem is her stepmom, my son's wife is a high conflict person, who I find has many if not all of the traits  of a BPD person.   She has interfered inour relationship with my granddaughter and every time she has found out we bought her something, clothes ect. She rants.   Long story short, she has alienated us from seeing our other three granddaughter and refuses to let us see them.  She feels we show favoratism, which I try hard not to do.  She never has made us feel welcomed.  The main problem we have, is she is telling my oldest granddaughter, her stepchild, she is not allowed to see us without her other children, but she restricts her children and now totally has alienated them.  My oldest granddaughter is so emotionally upset over this.  I need help.  My granddaughter is afraid she is going to get in trouble by seeing us.  My son is in the middle and it is a huge mess.

[newlifeBPDfree]

I'm sorry this is happening to you. What is your son saying about all this? Who is the BPD in this scenario?

[understandnow]

My Dil is the high conflict person.  My son just tries to keep peace.  I have always ignored her rants at me via texts.  This last text was telling me I would never see " her" children again because we have set limits on not letting her manipulate us from seeing my oldest granddaughter.   We love "her children" and there has never been any accusations of physical, mental or verbal abuse with our grandchildren.  She is just so crazy that my son has been involved with his oldest the last 3 years of her life.  She dislikes the child and never says anything nice about her and always sees the bad in her.  everytime she finds that we picked my granddaughter up it triggers a rage in her.  However on numerous occasions we attempted to see our other grandchildren, we are severely restricted and then we are accused of never picking them up.  The mother of my oldest granddaughter has always encouraged our relationship and my Dil has turned me down against my son's wishes on numerous occasions.

My oldest granddaughter lived with my son and Dil for about a year and was taken away and given back to mom due to verbal and emotional abuse from my Dil via a custody courts battle.

My son has a good relationship with us and feels she is being unrealistic and cannot do anything.