Hanna Tanasova (28) died after being involved in a collision on December 5 in Lisnaskea, Co Fermanagh.
She passed away on Friday, however, the PSNI only confirmed her death on Tuesday.
The Ukrainian national, who was living in Mayobridge, Co Down, passed away in hospital.
She is the fourth person to die on Northern Ireland’s roads over the Christmas period.
Chief Inspector Simpson from the Collision Investigation Unit, stated: “Officers responded to a report that a Vauxhall Insignia car and Renault Traffic van had collided on the Crom Road at around 4.40pm.
“Colleagues from Northern Ireland Ambulance Service and Northern Ireland Fire and Rescue Service also attended the scene and a number of people were conveyed to hospital.
“Sadly, 28-year-old Hanna Tanasova, who was originally from Ukraine but had been living in the Mayobridge area for several years, passed away from her injuries in hospital on Friday 26th December.
“Our investigation is ongoing, and we appeal to anyone with phone/dash cam footage, or information which might assist, to get in touch.
“You can get in contact with officers on 101, quoting reference number 989 of 05/12/25.”
Hannah Tanasova
Funeral of Callum McVeigh takes place in Co Down
Separately, two other people died on Boxing Day after road accidents.
Angela Feenan, who was 73 and from the Downpatrick area, died in a two-vehicle collision. Another man was taken to hospital, police said.
The accident happened on the Ardglass Road, Downpatrick.
Also on Boxing Day, Pádraig McDonald died after a collision near Cookstown, Co Tyrone.
The 20-year-old was from the Loughmacrory area.
A teenager also suffered “life-changing injuries” and several others remain injured.
In another incident, young footballer Callum McVeigh also died after an accident on Christmas Eve.
He was 23 and from the Crossgar in Co Down.
The PSNI said Mr McVeigh died following a single-vehicle accident involving a forklift which occurred on a laneway off the Holywood Road in the Craigantlet area of Newtownards.
Mr McVeigh played for Killyleagh Youth Club from Amateur League 1B.