“Who’s ever heard of a country singer from Glasgow?”

So says Rose-Lynn (Jessie Buckley, “Chernobyl”) of herself, despairingly, in “Wild Rose,” a unique and gritty spin on the rising-star genre. Singer/actor Buckley, a former BBC talent show competitor who can belt them out to rival Lady Gaga, plays a fiery Scottish ex-con and single mother of two small children.

An anomaly in the land of bagpipes, she’s got a deep and abiding love of American country music (not “country and western,” as she frequently corrects fellow Scots) and aims to be “the next Dolly Parton,” as her fellow inmates yell upon her release.

Julie Walters co-stars as Rose’s frustrated mother, Marion, who’s trying to temper her daughter’s Grand Ole Opry aspirations with the realities of parenting. When Rose takes a job as a maid for a wealthy family, her boss (Sophie Okonedo) gradually becomes a mentor of sorts — while being kept in the dark about Rose having kids.

Nicole Taylor’s clear-eyed screenplay never veers into melodrama, but it does have two heart-tugging secret weapons in wee actors Adam Mitchell and Daisy Littlefield as Rose’s children, who stare accusingly at her with wide eyes as she fobs them off on sitters and their grandmother again and again to chase singing gigs.

The scrappy striver narrative may be an overly familiar one at this point, but director Tom Harper (the BBC’s “War & Peace”) gets a terrific performance from Buckley as Rose chases her dreams while living the kind of turbulent life that has always inspired the best of country songs.