She is growing in confidence all the time.

她的信心在不断增强。

She's not usually lacking in confidence.

她平时并不缺乏自信心。

We told you all these things in confidence.

我们告诉你的这些事情都是保密的。

As she grew older she gained in confidence.

随着年龄的增长她的信心增强了。

Eva told me about their relationship in confidence.

伊娃对我透露了他们俩的关系这个秘密。