Any noise—even the (very) least—would startle her.任何响声——即便是最（微）小的声音——都会吓着她。

That's the least of my worries/problems. [=I have more important worries/problems to deal with]那是我最不担心的事情/问题。

We had many things to consider, not the least of which was the safety of our children. [=the safety of our children was very important]我们有许多事情需要考虑，尤其是孩子们的安全问题。