Brooker was educated at Hawarden Area School in North Canterbury from 1970 to 1982, and was dux of the school in her final year there. She went on to study chemistry at the University of Canterbury, first graduating Bachelor of Science with first-class honours, and then completing a PhD titled Synthesis and characterisation of polynuclear complexes with macrocyclic and related ligands under the supervision of Vickie McKee in 1989.