She confirmed she had smoked methamphetamine and used ecstasy but said the drugs came from Loffley who sold cannabis.
Ms Lawrence said Loffley was a jealous and violent man who beat her and once throttled her in their kitchen until she stopped breathing. "He nearly killed me."
Asked by Loffley's lawyer Roger Chambers why she did not leave or phone for help, Ms Lawrence said she came close to leaving him but found out she was pregnant and wanted to stay for the child that was on the way.
"... I loved him at the time and love makes you do stupid things."
She said on the day of JJ's death, Loffley had been looking after the child while she went out to get a bank overdraft.
Ms Lawrence said she had wanted to take JJ but Loffley had insisted the child stay at home.
"I was too scared to take him because he might give me a hiding for not listening."
She said she was in a bad mood with Loffley when she got home and put herself to bed because she was coming down with the flu.
The court has heard that Loffley told police the child had been bouncing on the bed when he fell off and landed on his chest.
Mr Chambers asked Ms Lawrence if she had "lost it" and been violent with JJ.
Ms Lawrence denied ever hurting her son.
Mr Chambers also asked questions about JJ's funeral and whether she had told Loffley "I did it".
Ms Lawrence replied: "I didn't say that. If he says that, he's wrong and he's a liar."
She said the night of the funeral, she and Loffley were in bed.
"He asked me: 'Do you think I did it?' and I said: 'Yes'."
Ms Lawrence confirmed she had said to her cousin she might get between five and six years in prison because JJ's death had been an accident.
"I said that because I felt I was to blame, even though I didn't do anything. I felt like I was to blame because I am the mother."