Lady Bird is a semi-autobiographical film written and directed by Greta Gerwig with a plot synopsis that need not detain us as it is basically only this: girl has a mum. (Or: girl has a mum, and sometimes they row and sometimes they don’t.) But thus far it has won near universal critical praise, two Golden Globes and five Oscar nominations, thereby proving there is mileage in girls and their mums, and box office in girls and their mums, and that girls and their mums can be more than mere afterthoughts.