It sounds like a classic scam unfortunately, lots of clues in the text such as ridiculously high salary, sob story, etc.

But the biggest clue of all is that this person is asking you to take the job without knowing you, without interviewing you, without checking if you'd be a good caretaker of the child

Keep away from anything like this, especially if it's unsolicited - these people are hardly worth the energy you need to press 'delete' :-)