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.
Take a look at these eggs, which were cooked in fully boiling water for times ranging from 1 minute to 15 minutes: As you can see, not one of them is a perfect hard-cooked egg: the eggs go directly from having slightly translucent centers to having rubbery whites.