The mother of two children has been charged with their murder at a special sitting of Mullingar District Court this evening.
48-year-old Lynn Egar - with an address at Winetown, Rathowen Co Westmeath - was charged shortly after 8pm this evening.
Five-year-old Thelma Dennany and her two-year-old brother Mikey died in the car fire which happened on the Coole to Multyfarnham road on September 9th.
Lynn Egar did not address the proceedings following a five-minute hearing.
She was remanded in custody to appear again at Athlone District Court via video link on September 28th.
The children's mother was detained under Section 4 of the Criminal Justice Act on Wednesday.
Detective Sergeant David Donnelly told the court that he charged her with two counts of murder at 7.22pm.
"In reply to charge after caution she made no reply," he said.
She was remanded to the Dochas Centre, the women's unit of Mountjoy Prison, in Dublin.
A passerby came across their car engulfed in flames at Lackan, a townland on a rural road linking the villages Multyfarnham and Coole.
The mother-of-four and toddler Mikey were pulled out of the vehicle, and later emergency services found the remains of Thelma inside the car.
Reporting by Tom Tuite