In most cases of first trimester Vanishing Twin Syndrome, there is no physical impact on the surviving twin. A healthy womb experience followed by a normal delivery should be expected. A late pregnancy occurrence of VTS does have some implications for the surviving fetus, just as for the mother.
Depending on how cooked you like your hard boiled eggs, the eggs should be done perfectly in 10-12 minutes. That said, depending on your altitude, the shape of the pan, the size of the eggs, the ratio of water to eggs, it can take a few minutes more.
Lower your eggs straight from the fridge into already-boiling water, or place them in a steamer insert in a covered pot steaming at full blast on the stovetop. If boiling, lower the heat to the barest simmer. Cook the eggs for 11 minutes for hard or 6 minutes for soft. Serve.