Thanks again to everyone for the supportive and kind messages. I am in a bit of a state today after daughter had scan yesterday which confirmed the diagnosis.
As suspected, her complications mean she has a 40% increased chance of premature labor, and a risk of massive hamemorage if she doesn't get to a hospital within 20 minutes if she a) bleeds or b) goes into labor.
She's scheduled for a C section in 3 weeks, but I'm terrified this could be too late.
We all live 40 minutes from the hospital and, as her husband is away next week, she will be alone. The Royal College of Obstetricians advice is that she should be in close proximity to the hospital and in constant presence of a companion. We have suggested she move for a few weeks to a hotel near the hospital (which they can afford) but she won't have it. We have begged her to come stay with us while her husband's away but so far she says no.
Meanwhile at least now the doctors have told her she must rest and not do heavy work, so she has stopped insisting she can do all the heavy lifting/shopping (her husband does none of it and is happy to watch her carry gas bottles etc). We will of course do this for her (as always when it is necessary) but it is not always possible as we are not always there to intervene.
My daughter's life is at risk, there is no doubt about this, it is not only the baby. I am at my wit's end, so sorry if not very coherent.