A family friend will be visiting us in Canada for two months. In case she gets a stamp at airport limiting her stay to one month, she will need to either (1) extend her stay, (2) re-enter to Canada via US. I was told that I could drive her to the US make a U-turn and bring back to Canada, and she will get another stamp on her passport at Canadian border. Does anyone had similar experience. Would the US really let her go through the US border without having the US visa? Thank you!