I'm so sorry Hels that you've been estranged
and yes, I'm afraid it is time to draw a line.
The gifts you've been sending your GD appear not have been passed onto her, and it could be that the money hasn't been either. Your D is being very cruel to you and your GD, to say you may send these gifts if they are not being given to her.
You could open a savings account in your name, and put money in for her birthday and at Christmas. Have this account specifically mentioned in your will with your GD as beneficiary.
Far from ideal I know, but at least there will come a time when she'll know that she was always loved by you and never forgotten. You could also get birthday and Christmas cards for a memory box, which will also be left to her in your will. This is what we do for our GC, not much but at least it's something.
For those of us also estranged by an adult child, you don't need to find the words to say how you feel, we know and understand.
There's a support thread on this forum which you may find helpful. It's helped many over the years and I've been posting there regularly for 10 years.
The pain never goes away but it does get easier with time and for me, I was only able to begin to heal when I accepted that our relationship with our son and only GC was over, and there was nothing we could do about it.
Taking care of yourself is what you need to do and the first step is protect yourself from any more hurt.