Her baby sister bother her for candy.

她的小妹妹缠着她要糖果。

You've got a baby brother and a baby sister.

你有一个小弟弟和一个小妹妹。

My baby sister can walk a little already.

我的小妹妹已能走动几步了。

She must care for her brother and baby sister.

她必须照顾她弟弟和襁褓中的妹妹。

My baby sister never cries unless she is hungry.

我刚出生的妹妹除非饿了，她是从来不哭的。