She’s a nice kid, from a nice family. And, in Julia Hart’s winning and wise “Don’t Say Good Luck,” we watch that nice kid and her nice family take on the kind of everyday tragedy too many people are forced to endure. ‘Don’t Say Good Luck’Hart and her husband and producer Jordan Horowitz co-wrote the script alongside Laura Hankin, who was inspired by her own experiences with similar material. This is, then, a great compliment: this is a nice film, about a nice kid and a nice family and some terrifyingly common issues. Grade: B“Don’t Say Good Luck” will start streaming on Netflix on Friday, August 14.