How sad. In this case, the "sins of the father" are visited on not only on the next generation, but the previous one, as well.

Good luck.

There have been legal cases that were decided both ways, in favor of the grandparents having a continuing relationship, and against the grandparents having any contact with their grandchildren.

Thankfully, they are teenagers, so in a few years they can make their own decisions as to who the spend time with.

IC 31-17-5-2
Best interest of the child; in chambers interview of the child
Sec. 2. (a) The court may grant visitation rights if the court determines that visitation rights are in the best interests of the child.
(b) In determining the best interests of the child under this section, the court may consider whether a grandparent has had or has attempted to have meaningful contact with the child.
(c) The court may interview the child in chambers to assist the court in determining the child's perception of whether visitation by a grandparent is in the best interests of the child.
(d) The court may permit counsel to be present at the interview. If counsel is present:
(1) a record may be made of the interview; and
(2) the interview may be made part of the record for purposes of appeal.
As added by P.L.1-1997, SEC.9. Amended by P.L.15-2004, SEC.3.

IC 31-17-5-3
Petition
Sec. 3. A proceeding for grandparent's visitation must be commenced by the filing of a petition entitled, "In Re the visitation of _________". The petition must:
(1) be filed by a grandparent entitled to receive visitation rights under this chapter;
(2) be verified; and
(3) set forth the following:
(A) The names and relationship of:
(i) the petitioning grandparent or grandparents;
(ii) each child with whom visitation is sought; and
(iii) the custodial parent or guardian of each child.
(B) The present address of each person named in clause (A).
(C) The date of birth of each child with whom visitation is sought.
(D) The status under section 1 of this chapter upon which the grandparent seeks visitation.
(E) The relief sought.

I'm in the very early stages of this process in NJ. Indiana has a portion of the code that is very wise: the child may be interviewed and asked if he/she wants to see the grandparents! New Jersey doesn't have that.

You're fortunate in that your grandchildren are older and able to speak for themselves. Mine are only 3 and 5 and as my attorney advised me there's usually no history from a child wherein he/she might have expressed a meaningful desire to see the grandparents.

In NJ, the court can order visitation even though the family is intact, which my daughter's is - it's just extremely dysfunctional, with abuse, big-time anger problems, gender identity issues, denial and depression all going on.

The parents deal with problems with other family members not by addressing them but by telling the family member that they cannot see the grandchildren, i.e., if you don't do such-and-such because I demand it, you won't be able to see the children. Or, because you said such-and-such about my spouse you cannot see the grands.

Lots of emotional abuse, brainwashing and isolating going on.

My attorney has advised that we will proceed to focus on the dysfunctionality in pressing our case to be allowed visitation, i.e., the parents cannot make healthy reasoned decisions.