She said Emily had emotional and health problems from her life in New Zealand, where she moved to when she was nine before returning to Bournemouth as a teenager.
Anita Turner told the jury Emily often stayed at her home and had confided in her.
"She was very easy to get along with. She loved to be at ours. She seemed really lovely."
She denied she knew the teenager was dead for an hour before calling an ambulance.
Anita Turner told the jury that on three past occasions, she had tried to wake Emily when she was staying in her son's room, but she did not respond.
On one occasion Emily took 25 minutes to wake up because she had been drinking the night before.
But on the morning of May 7 last year, Emily did not wake up.
Anita Turner said her son asked her if she could wake up Emily. She tried to wake her by calling her name and tapping on the duvet.
"She didn't wake up. I didn't think anything at all. I made a cup of tea and I still called her," she said.
Anita Turner said she climbed onto the bed and tried to make Emily sip the tea, but her mouth did not move.
"I called Elliot and we were both trying to wake her - we kept shaking her."
Asked why she did not call an ambulance, Anita Turner said she did not think Emily was dead.
The prosecution alleges Elliot Turner confessed to killing Emily in a letter to his mother.
Anita Turner denied destroying the letter, saying she did not know anything about it at the time her husband Leigh, 54, found it and allegedly ripped it up.
She also denied she had perverted the course of justice by removing a family friend's coat from Turner's room when police allowed them into the house the day after Emily's death to collect some belongings.
She said a police officer saw her take the jacket.
The trial is continuing.
- APNZ
