结合上下文有以下两种翻译：
Who are those people that/who are talking to your mother?
Where are those people from that are talking to your mother?
再问： 从句不是要紧跟在先行词后的吗，为什么中间有个 that 呢
再答： 这里的 that或who 就是引导从句的，代指 those people 很久不解释语法了，不过没有问题的，呵呵~
再问： 解释一下，that 是from后的那个。为什么that在from之后呢，不是应该在people之后的吗
再答： 英文口语表达的习惯而已，from 放在最后会“头重脚轻”的，类似的还有用 It's 开头的： It's difficult to do sth. 如果用 To do sth. is difficult 也不错，但习惯用前者。 Where are those people that are talking to your mother from？ 也不错，但英文不习惯这么表达，如果真是死抠语法就没意义了吧，语言是活的，应用最重要。
