In a characteristically sterile courtroom at the NSW Coroners Court in Lidcombe four small, bright paintings stood atop the witness stand.

Looking as though they belonged in a gallery, they were from the hands of two siblings, aged just 10 and 11 at the time they died.

Maria Lutz and Fernando Manrique with their children, Martin and Elisa.

Sitting at the bench beside them Deputy State Coroner Elaine Truscott said the artworks, lauded by the promising children's school community, gave her pause to reflect on the talent of the prodigies whose lives were snatched by somebody who "should've been their protector and provider".

She was delivering the inquest findings into the deaths of Elisa Manrique and her younger brother, Martin, as well as their Colombian-born mother Claudia Lutz and father Fernando Manrique, who had killed his family and himself by pumping carbon monoxide through their Davidson home between October 16 and 17, 2016.