Sundance film festival: The often under-utilised actor gives a monumental performance as a mother on the edge in an exhausting spiral of a movie

Last year’s toothless adaptation of Rachel Yoder’s Nightbitch, premiering then disappearing during fall festivals, tried to bring attention to the specific hell of motherhood. But valid points were clumsily underlined, highlighted and circled by a heavy hand, a missed opportunity that’s now been pushed even further in the shade by Mary Bronstein’s superior Sundance offering, the suitably aggressive-sounding If I Had Legs I’d Kick You.

It’s a far darker film (A24 vs Disney) but it focuses on a similarly fatigued mother, exhausted not just by the act of childcare but by the total lack of awareness and assistance afforded by those in her life. She’s played here by Rose Byrne, someone who has long deserved something more substantial to sink her teeth into,...