She said 'hi' with the blithe assurance of someone who knew how much she'd been missed. 主谓宾状。主语是 she，谓语动词 said，宾语 hi，with the blithe assurance of someone who knew how much she'd been missed，是介词短语作状语。who knew how much she'd been missed 是 someone 的定语从句，该定语从句中 how much she'd been missed 可以看作感叹句作 knew 的宾语从句。
