Esther Waitherero, the late retired president Mwai Kibaki's only surviving sibling, has died aged 115.

This is according to a statement released by her son Francis Githinji on Thursday confirming her demise.

Waitherero passed away surrounded by members of her family at her Gatuyaini family home in Nyeri while she was receiving treatment.

Her passing on comes barely four months after her younger brother, Mwai Kibaki, died.

Waitherero is the one who raised and took care of the late Kibaki and his brother Nderitu while growing up, according to a revelation she made during an interview with a local media.

Late Mwai Kibaki. PHOTO/COURTESY

She became widowed before independence when her husband died leaving her to care for their several children.

Waitherero was a tea farmer who lived a simple life which revolved around her large tea farms from where she eked a living.

Her family said it is grateful for her life, which it termed as "rich and well lived".