We told our 7 1/2yo DD as soon as we found out at about 6 weeks. Understandably, she's a lot older than a lot of your children, so she took the news easily.

We too have had enough experience with death and have been very open about it with her. The basics of it being that people die because they are either a) too old, b) too sick or c) too injured. If we had m/c we would have told DD at the same time so we could grieve together, knowing she would understand that the baby's wasn't well enough to grow into a baby who could live outside my body. Fortunately that hasn't happened, however we have still mentioned that anything can happen and although 'Squishy' is big and strong, "it's not over til the fat lady sings".

All the best with your decision.

Cheers,
Rachel