When my collie knew it was his time he refused food and water. I used a dropper and gave him some water anyway, but as for food, he would not even take a piece of turkey. He was sweet, though. Sweet to the very last second.
I say that to say, your dog knows it is her time. She just needs to know you love her and she will go in peace.
You are right. It’s very hard to keep “hovering, coaxing, and cajoling” trying to put off that moment, though...but you are right.