Aggie Di Mauro fronted court and stared down Luay Sako as he pleaded guilty to her 23-year-old daughter’s murder in 2020.
It was alleged the man stalked Celeste for a year before he smashed into her family home and stabbed her to death as she slept.
The 37-year-old developed an obsession for her when the pair worked together at a call centre in Melbourne, Australia.
The court also heard he bombarded her with more than 150 texts and social media messages on the fateful evening.
Up until Thursday, April 6, 2023, Sako had refused to plead guilty and used mental impairment as his defence.
But psychiatrists investigating the case have now rejected his claim and subsequently he pleaded guilty to the brutal killing.
Aggie, Celeste’s mother, told 7News that the guilty plea should not be taken as a sign of remorse.
She said: “To actually finally hear him admit it, to actually get to yesterday and hear him plead guilty, was quite shocking.
“I’m never going to understand why we’re expected to see that as a sign of remorse.”
A guilty plea must be considered by the magistrate when sentencing.
The earlier the offender pleads guilty, the greater reduction they would likely receive.
Following Celeste being laid to rest, her mum has visited her grave every day since.
She said: “This is where I have to come to spend time with my daughter.
“I need to live with the fact that I was at home when this happened, she lived at home, and I was too late to stop anything.”
At the time of her tragic death, boyfriend Chris Ridsdale, paid tribute to her via social media.
His post read: “Celeste was the kind of person who lit up a room as soon as she walked in.
“I am fortunate to be able to say I’m one of the lucky few who she considered her closest friends and even luckier… she chose to share her love with me.
“To have known Celeste was to have been blessed.
“Such a kind, caring and selfless soul who had an impact on everyone she came into contact with.”
Sako will appear in court again later this month.