Being apart from the grandchildren

Have you tried direct contact with your dil? Maybe write her a letter just asking if you can write to the the children direct.

I am afraid that it is on your son's plate to facilitate a relationship with his children, not your your ex dil.
I would recommend to talk to your son if you are not happy about that.

Hi yes my son sees the children every other weekend but he lives in Wales and the children live in Derbyshire and we live in Norfolk. For some reason my ex d.i.l will not let me Even talk to them, so I can only talk when they are with my son which is twice a month. She was like the daughter we never had and we got on really well when they were married so I am so confused and finding it so hard, it’s been 2 years now and hasn’t got any better.

Welcome Nanniesuelp. Is your former d.i.l. preventing you from seeing your GC? Does your son have regular contact with his children and if so, is it not possible that you can arrange to see or at least contact them through him?

You are not on your own. Some find themselves estranged because of their children's divorce and others because it's our own child who has estranged us.

Divorce can leave feelings of bitterness and anger but I've never understood why one parent feels the need to punish his/her former parents in law, their children's GP's, be taking away their GC.