Police on Saturday arrested Suhaila Mwalim Bakari who was romantically involved with one of the attackers at the DusitD2 hotel-complex.
Suhaila was at one point reportedly married to Mahir Khalid Riziki.
Riziki is the suicide bomber captured by a CCTV camera blowing himself up.
Residents said Suhaila is a trader in Bakarani slums and was married to the attacker until 2014 when he went hiding after he became one of the most wanted terror suspects in the area.
After she was left alone, the light-skinned lady moved on with her life and got a new flame who rekindled her love life.
The new lovers got a child together who is now three years old.
Anti-Terror Police Unit officers have however marked Suhaila suspecting that she had been in constant communication with the attacker during his time hiding in Somalia.
They also suspect the suicide bomber had travelled to Mombasa last year before he vanished only to return on January and stage a deadly attack that left up to 21 people dead.
The Standard reported that the police want to establish whether Suhaila had been receiving any material support from her estranged lover or his networks in Somalia.
They will also seek to establish why she remained mum on his whereabouts despite having been a most wanted suspect with a Sh2 million bounty on his head.
Also arrested is the attacker’s father.
Bakarani residents who know the lady said she is soft-spoken and a hard-working trader.
“She can’t hurt even a fly,” a resident said.