South London schoolgirl Tia Sharp "idolised" the man accused of murdering her and was "his cling-on", a court heard.
Jurors at the Old Bailey were read a statement by Tia's grandmother, Christine Bicknell, whose former boyfriend, Stuart Hazell, is accused of murdering the 12-year-old.
She said: "When Tia went missing it didn't cross my mind that she could be dead.
"I always thought she was coming home. It didn't cross my mind that he would hurt her. He loved Tia, she idolised him.
"I love Stuart with all my heart, he was my world, but my grandchildren always came first."
Tia would frequently stay at her grandmother's house in New Addington, south London, and would ask Hazell if she could stay before she asked Ms Bicknell, the court heard.
In the statement, read by junior prosecutor Jocelyn Ledward, she said: "Tia will ask Stuart if she can stay for the weekend before she asks me.
"The majority of the time he has her more than what I do. She is his cling-on."
Hazel (aged 37) of New Addington, is charged with killing the schoolgirl between August 2 and 10 last year.
Her body was found in the loft of her grandmother's house in New Addington a week after she went missing.
Ms Bicknell said all her grandchildren "loved him to pieces".
She said she had thought back over her relationship and had not noticed any particular changes, nor had any worries about Hazell being around Tia.
Her statement said Hazell was not somebody she "dragged in from the street", but had had a relationship with him for five and a half years.
"Tia was not the sort of girl you could groom," she said. "She was a mouthy 12-year-old - you couldn't force her to do anything.
"She is a mini Natalie (Tia's mother), which is a mini-me."
She added: "I knew nothing about her death. If I knew, he could be dead - I would be inside because I would have killed him.
"I found out the same time as everybody else, that Friday. I didn't know anything."
Ms Bicknell said that Hazell would get "argumentative" after drinking vodka, but that she had told him not to consume it in the house.
He would, however, drink lager and smoke two cannabis joints per day.
Hazell, who had previously dated Tia's mother, moved in with Ms Bicknell a week after their relationship started in 2007, the court heard.
Earlier junior prosecutor Jocelyn Ledward went through phone records detailing text messages sent by Tia and Hazell.
They showed the 12-year-old arranging to meet him at a train station in Croydon on August 2 last year.
That evening Ms Bicknell spoke to Hazell on the phone, and said she had heard Tia laughing in the background.
The records showed Tia's last BlackBerry message was sent at 00:42 on August 3, and revealed that later that day Hazell called the 12-year-old's phone, after he had allegedly killed her.
The week after Tia disappeared, Ms Bicknell described a "smell" coming from somewhere in the house.
"On the Thursday night I noticed a smell in our house. It seemed to be coming from the small bedroom," she said.
"I had a quick check around and I couldn't find anything. I had that smell before in my house and it was cat's mess.
"The following morning I could smell it a bit worse than before."
She said she had apologised to the police for the odour, telling them: "I'm very sorry, there's a horrible smell up there, one of the cats has shit somewhere and I can't find it."
Ms Bicknell's statement said they had no internet access at the house.
"Stuart didn't have access to the internet, he wouldn't have a clue how to do it, so he says," she said.
The court has heard that Hazell looked at indecent websites, searching for material on under-age girls.
Ms Bicknell said: "Stuart doesn't use the internet as far as I know. I have been asked by the police if Stuart watched or downloaded pornography to his phone. I have never seen him do anything like that."
She said she had seen some pictures on his phone, but he claimed they had downloaded accidentally when he was looking for something else.
The grandmother said she did not know why Hazell's semen had been found on the floor in Tia's bedroom, or why an Umbro top with bloodstains on it was found in her loft.