Could be tough if she had to be, but basically, she was a really nice person.

在必要时可以非常严厉，但基本上她是个非常温和的人。

I can tell she's a really nice person.

我可以说她是一个非常好的人。

And to separate in your own mind that you can be tough on the terms of the negotiations and still be a really nice person and still figure out what they want - show empathy.

在你自己的想法中，你可以对谈判条款采取强硬态度，但仍然是一个非常好的人，并且仍然弄清楚他们想要什么 - 表现出同理心。