Her inner thoughts were carefully guarded and never shared with others.

inner 是形容词，由 in（在...里面）加后缀 -er 构成，表示"内部的、内心的"。 thoughts 是名词 thought 的复数形式，thought 意思是"想法、思考"。 inner thoughts 指"内心深处的想法"，即不轻易对外人表露的真实想法。