Thank you so much everyone for your warmth, advice and support. The shock and numbness is beginning to fade a little and I have moved from a position of not being able to look at the photos of my existing DGD because of the pain, to the stirrings of a deep, deep love, even though I have not yet met her.
DH had a very long conversation with DD last night and I was pleased that he did. A lot of issues were talked through and he is capable of being much more measured about things, whereas I get emotional and upset. DD clearly has a different perspective on things, even though DH though that some of her responses were quite irrational. I think that whoever said that she is confused is absolutely right. Since she is with her husband 24/7 (he doesn't work at present) and hardly sees anyone else, she doesn't have any other perspective.
DH explained how hurt we were and apparently she agreed that her actions were hurtful although she seemed quite defensive. Anyway, it seems that she does want to have a relationship with us - and I hope with her sisters in due course, although they are not very amenable at the moment as they have been hurt themselves by being abruptly cut off and because they feel sorry for us. However, DD2, who is staying with us at present, and says she never wants to have a relationship with DD1, was very taken with the pictures of the baby, now a toddler so hopefully, in time, there is a prospect of all round healing. The advice given by the lovely Gransnetter to be positive was very sound.
DH has suggested a meeting in January (at her place which is about 5 hours away) and to take things very slowly, which seems a sensible approach. That gives time for the dust to settle and to come to terms with things. The last thing we want is to travel a long way and end up having an argument or upset her in late pregnancy.
I don't think it will be a problem forming a relationship with both DGC - hopefully - as I will meet them both at the same time, which is another good reason to leave it until early in the New Year. Part of me wants to just jump on the first train and go and see DGD1, but I feel that DH is right in recommending caution. I have reached the view that it is better to rely on his judgment as mine is so clouded that I can't think straight at present.