When Sophie Bennett moves from a quiet sleepy suburb of Toronto to glitzy west London, she doesn't know where she has landed: Venus or Mars. Her three-year-old daughter Kaya attends Cherry Blossoms, the most exclusive nursery in London, where Sophie finds herself adrift in a sea of Alpha Mums. These mothers are glamorous, gorgeous, competitive and super rich, especially Kelly, the blonde, beautiful and bitchy class rep.

Struggling to fit in and feeling increasingly isolated, Sophie starts 'The Beta Mum', an anonymous blog describing her struggles with the Alpha Mums. But when her blog goes viral, she risks ruining everything for herself and her daughter. How long will it be until they discover her true identity? Is her marriage strong enough to survive one of her follower's advances? And will she ever fit in with the Alpha Mums?