Thank you everyone for your replies and kindness. Thank you also for asking about DD2. She has a few more tests still to be done, but all looking quite positive at present - everything crossed and touching all the wood in sight, as Fate hasn't been very kind recently.
I don't think DD1 is enjoying any feeling of power, I genuinely think that she would just have liked to carry on as though nothing had happened, and that we are all unreasonable, especially her sisters, because this is not the case. There was a bit of a rapprochement after DH died, but now everyone is getting on with their lives and, unfortunately, they are not part of each other's lives.
She seems content with her own life with LB and the DGDs and is excited by their plans, as well as expecting DGC3, which is understandable. She must be so busy both practically and with her DC, that she probably doesn't have much space in her head for anyone else although, as a PP said, she has always been very self absorbed but then, many people are. DH didn't think either of them had much empathy, and he hardly ever said a word against anyone.
When she first got back in touch, after she had ghosted us for six months, the intention was clearly to request money in connection with the house move. At that stage, our house had just been razed to the ground (fortunately it was just after we had moved out), so there were a lot of memories as it had been the family home, and it was all really upsetting. A few days later, our cat was run over, and then DH's aunt, the one whom she has recently inherited from, was rushed into hospital after a stroke. She knew all of these things, but showed no real sympathy or interest.
To be fair, I think there has been some improvement with maturity, but there is still a way to go, not helped by the fact that she regards LB as a role model, as will the DGC. The next scan is in a few weeks and it is clear that LB wants a boy. I just worry that if it's another DGD, she will keep having more DC.
I will not 'feed the beast' by becoming involved in any detailed conversations, but I am hoping that by passing on the books, they will approach things a bit more sensibly. It's just basic stuff like having a business plan, inspecting the plot before you buy, carrying out soil tests etc. But we shall see....it's up to them and clearly something which they are keen to do.
I am alright and I don't expect to lean too much on any of my DDs, it's is for me to rebuild my life and try to move forwards. They say that the past is a different country and that's how it feels, a long ago holiday of halcyon days, but now sadly over. I took myself to the seaside yesterday, as it was such a lovely day, but ended up feeling quite sad and melancholic, seeing all of the couples go by, hand in hand, some clearly a lot older than DH and I. There was an elderly couple on the next table to me, at the outdoor cafe where I stopped for lunch, with their two grandsons. They were obviously so happy and close, with the smaller boy climbing onto his grandmother's knee. Why couldn't this have been me and DH? But useless to think such thoughts.
Sssloou is right, as always, in saying that I need to practise some mindfulness techniques. I also need to be busier, which I will be from next week, so I don't have so much time to wallow. However, the bereavement advice is that you need to fully experience your feelings in order to come to terms with the loss.
I know that this is controversial, but I have readings with two mediums/spiritualists early next week, who have been recommended to me. I have an open mind, or at least that's what I am telling myself, to guard against disappointment. I didn't feel ready before, but now I think I am prepared to see what transpires.