Conversation so far:
Was Mwai Kibaki married?
President Kibaki was married to Lucy Muthoni from 1961 until her death in 2016.
Did he remarry?
In 2004, the media reported that Kibaki has a second spouse, whom he allegedly married under customary law, Mary Wambui, and a daughter, Wangui Mwai.
Did he have any other children?
They have four children: Judy Wanjiku, Jimmy Kibaki, David Kagai, and Tony Githinji.
Did he have children with anyone else?
CANNOTANSWER.
Are there any other interesting aspects about this article?
Ms.
Wambui, the rather popular "other woman", who enjoyed the state trappings of a Presidential spouse and became a powerful and wealthy business-woman.

Question: What kind of power did she have?
Self-contained rewrite: What kind of power did Ms. Wambui have?