Trader Joe's frozen foods and sweet treats make the drive from Canada worthwhile.Karen HabashiI'm a Canadian mom who drives to the US just to stock up on my family's favorite Trader Joe's items.My kids love the store's fettuccine Alfredo, mango juice smoothies, and vanilla meringues.The Middle Eastern-style kebabs and Mandarin-orange chicken make weeknight dinners a breeze.As a mom of three picky eaters, I will do whatever it takes to find foods…