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? If Kristin Scott Thomas’ “My Mother’s Wedding” never quite reaches the heights of that well-worn genre, it is not for lack of trying. 

Equal parts Anton Chekhov and Richard Curtis, her directorial debut ends up being a sweet if rather modest family affair. The premise of “My Mother’s Wedding” is as straightforward as its title suggests. Sisters Katharine (Scarlett Johansson), Victoria (Sienna Miller), and Georgina (Emily Beecham) gather for one weekend at their childhood home to bear witness to their mother’s third wedding. Twice-widowed Diana (Scott Thomas) has seemingly found love again.

 Only, what’s supposed to be a celebratory family weekend instead becomes an emotional ticking bomb as each of Diana’s three daughters (a Navy officer, a movie star, and a nurse) is forced to grapple with their tragic pasts, their stunted presents, and the glimmers of possibility that await them in their futures ahead. 

Lording over this sun-dappled weekend in the English countryside (“Wild” and “Big Little Lies” cinematographer Yves Bélanger opts for a brightly lit aesthetic throughout) are the memories of the fathers these three now-grown-up girls cannot seem to let go of. Katharine has gone into the Navy like John Frost, her and Victoria. And while his death in action makes for great talk show fodder for her sister, who is an actor, the stoic Katherine has devoted her career to honoring his memory instead. 

It may be why she struggles with how to honor Johnny Monson, Georgina’s father (and John’s best friend), who came into their lives for an all-too-brief moment before he, too, went missing in action. Such a fractured and tragic family story has evidently wounded her and made it all the harder for her to be more unguarded around those she loves and who wish to love her.