It think we brother section should be complete before then sleeping. While sister sleeping brother and are working on it. They don't know their mother watched by its address.
The brother also think that we should be completed before then sleep. While he's sleeping, and I am working on it. They do not know that their mother will sneak away.
The younger brother thinks that we should finish before I sleep. While you were sleeping and sister are working. They know that their mother sneaking away.