Did her behaviour seem unnatural in any way?

她有任何反常表现吗?

She has an unnatural smile on her face.

她脸上挂着做作微笑。

A mother who is cruel to her child is unnatural.

母亲对孩子残忍是不近人情。

Hunt and voracity are unnatural to him.

捕杀动物与贪食不是人类本性。