Most critics like Don’t Say Good Luck, and the praise gathers around two performances. Melanie Lynskey, as a mother whose cancer has returned, is named in nearly every review as the film’s emotional centre, and several call her work quiet and true rather than showy. Sunny Sandler, as the daughter preparing to lead her school’s production of Waitress, is credited with more range and maturity than the reviews expect from a teenage lead. The writing is praised for treating the diagnosis as something the family lives with rather than a countdown, and for keeping the high-school scenes light without making the rest feel trivial.
The spread is fairly wide. Two reviews are lukewarm: Radio Times finds a competent television weepie with flat characters and a self-centred protagonist, and The Times thinks the daughter shines while the film around her does not. Even admirers mention contrivances and thin supporting roles, and one notes the film skirts the grimmer realities of the illness.