Ok on sunday this week my mom and dad are taking me to Ilinois to see my cuzins and I need tips!?

So I just need help dealing with my youngest cuzin Lexie! Sounds like a good little girl right? WRONG!!!!!!!!! SHE IS EVIL! SHE: kicked her dog roxy cuz she was standing in her doorway nd wasnt sposed to come in, calls me a ''stupid head'', and just dosent listen and crys alot! SHE DRIVES ME TO THE POINT OF EXPLODING!!!! I HAD TO HID IN THE BATHROOM!!!!!!!!!!!!! SAVE ME!!!!!!!!!!!!!!!!!!! Thanks!!