Muthoni lives in Nairobi. Writing as Muthoni Muchemi, she has published over forty books for children. Muthoni is also a storyteller and has appeared on stage in many schools in Kenya and beyond. She runs workshops, incorporating storytelling, to help writers develop stories for children and teenagers. She is the chief judge of the Morland Writing Scholarships (UK), and has also judged the Caine Prize for African writers.