New GC

Kittylester is right, if the only reason for moving is to be be near your daughter then think very carefully. Your daughter may move on elsewhere then you are high and dry. It's a big step to take for this one reason, grandchildren are soon grown and your help not needed.
Consider your options carefully Ponymoore

Ponymoore, if anyone should consider moving then it must be your daughter. She is asking too much of you.

Congratulations, I'm thrilled for your daughter and you after so many years of trying.

But your life is where you live not where she lives. You would be giving up more than you would be gaining.

I do understand the dilemma you're in as my son and his family live hundreds of miles away from me.

I also think it's slightly unfair of your daughter to put you in this position.

And, might she move somewhere else?

And, would you be leaving the current family, who presumably rely on you, in the lurch.

This sounds a bit doormatty. Whatever your children want you wll consider it.

Forget,(for about) 10 minutes the expected new arrival and ask your self two questions
1) Do I really want to upsticks and move from an area where (presumably) I am settled and have friends and to some unknown part of the country where I know no-one, have no idea whether I will like it or not and I could end up very lonely.
2) If I had to move, is where DD lives an area I would like to live in? If it isn't do not move.

A lot of people in your situation have acted on the request without careful thought, carried away in a cloud of grandmotherly love, only to deeply regret the decision later for all kinds of reasons.

Think long and hard about your decision.

You must be very pleased for your daughter, but I think she is asking too much of you.

Apart from your relationship with your twin GD's, you probably have friends where you are now, and perhaps as members of clubs or societies.

By all means go and stay for sometime when the baby is born, but to ask you to up sticks and move house is unfair.