Speaking to ITV News, Imani's uncle Mitchum Brown described her as a "quiet, lovely, friendly girl" who had only just begun to grow in confidence.
Mr Brown explained how Imani had sickle cell anaemia as well as a hole in her heart, and how she would travel to Jamaica every winter with her family because the warm weather helped with her conditions.
He says Imani was an innocent victim of Friday's shooting and believes the gunman was taking revenge over a dispute with the cafe owner, who is Imani's cousin.
More top news
The death toll following the collapse of a six-storey building in Nairobi rises to 10 as fears grow for those still trapped in the rubble
Springwatch presenter Chris Packham describes his battle with depression as "great, hopeless vacuum".
A newly promoted police officer caused a sensation with local women on Facebook