A dysfunctional family gathering for a special occasion (be it a wedding or a funeral) has long served as a ripe dramatic backdrop for a reason. What better excuse to bring together a motley crew of characters who know exactly how best to push one another's buttons and dredge up long-simmering resentments in the process?

Kristin Scott Thomas draws on her own childhood losses for her directorial debut “My Mother's Wedding.” In the film, which she co-wrote, she plays a twice-widowed woman about to marry for