Mariatu is nine years old. She attends Walter Halls Primary School in Nottingham. She studies cello with Sarah Huson-Whyte, and she also plays piano. She has Grade 5 Distinction on the cello and she is studying for Grade 5 Piano.
She has performed with the Kanneh-Masons in a series of concerts around the U.K. and in Antigua and Barbuda. She has played concerts with her siblings for the Belper and Bath Music Festivals, in London, Nottingham, Southwell and Machynlleth. Mariatu performed with the Kanneh-Masons for The Prince of Wales and The Duchess of Cornwall in March 2017, and in a Kanneh-Mason concert at St Johns Smith Square, London in 2018.
Mariatu has appeared on several television and radio programmes with her siblings, including BBC World Service, Al Jazeera TV, Channel 4, BBC 1 The One Show and the BBC4 documentary, Young, Gifted and Classical. She has featured, with the Kanneh-Masons, in a documentary by CBS Television (USA).