In Tia's mother Natalie Sharp's victim impact statement, she said: "I haven't allowed myself to grieve yet."
The court heard that she wanted to get trial out of way first. She said that she had placed "ultimate trust" in Stuart Hazell and there were so many questions she wanted to ask him.
She said that when Tia was born her natural father, Stephen Carter, had left home and it was just her, her mother, her brother and Tia. She said of Tia "she was mine, nobody else's, I had someone to love."
She said that she had a always thought Tia would come home and could not imagine that anyone had hurt her.
"It's too hard for me to think she has really gone," she said.
The sentencing of Stuart Hazell has been adjourned and will resume at 2pm.
Speaking before Tia Sharp's body was found, Stuart Hazell told ITV News and criminologist Mark Williams-Thomas, he knew "deep down in his heart" the 12-year-old had walked out of his home before she disappeared and he was not the last person to have see her.
He said: "I know deep down in my heart that Tia walked out of my house. I know she was seen walking down the pathway, she made her way down that track. What happened after that. I don't know."
Today he changed his plea on the fifth day of his trial, admitting to the murder of the schoolgirl.
Mr Justice Nicol is due to sentence Stuart Hazell later today after the 37-year-old pleaded guilty to the murder of Tia Sharp.
Tia's father, Steve Carter, broke down in tears as Hazell changed his plea.
The development came after four days of graphic evidence during which Tia's mother, Natalie Sharp, frequently had to leave the courtroom, visibly distressed.
The prosecution case included a grotesque photograph of a girl alleged to be Tia after she died.
In the shot, a naked girl, whose face cannot be seen, is posed on all fours on a bed.Mr Justice Nicol is due to sentence Hazell later today.