The street is the divider, so you must use "across the street", meaning "on the other side of the street". You can't use "from the street" or "opposite the street". So only the first one is correct. She lives diagonally across the street from us. There's another useful word to know. It is "kitty-corner" (also sometimes "catty-corner"). It means "diagonally across something". So, you can say: She lives kitty-corner from us. :)

Not sure why you are working on this kind of questions. Hope you do not take offense, but it's not a good way to learn English