A jury has failed to reach a verdict after a baby drowned in the bath while her grandmother was out of the room.
Shirley Grenfell was accused of manslaughter by gross negligence following the death of Chanelle Grenfell on 26 December 2017.
The 53-year-old, of Illogan, Cornwall denied that charge and an alternative count of cruelty to a child under 16.
She is on trial at Truro Crown Court and has been released on bail while the prosecution "consider their position".
The court heard the baby's parents had left their 11-month-old overnight with Mrs Grenfell, a mother of four who has 12 grandchildren.
She left the girl in the bath for two minutes and did not realise she was underwater, jurors were told.
Prosecuting, Miss Jo Martin QC said the NHS advised babies and toddlers should be put into a bath filled with no more than 5cm (2ins) of water and should not be left alone for a moment.
She said the bath at Mrs Grenfell's house had 14cm (5.5 ins) of water in it at the time.
Chanelle was taken to the Royal Cornwall Hospital in Truro but was declared dead the next day.
In a 999 call Mrs Grenfell said: "I was in the bedroom just getting dressed because I had just had a bath.
She said she "did not realise" the baby was under the water.
Simon Laws, QC, defending, told the jury: "She was not taking a risk, she was making a mistake.
"She is not blameless here, far from it, but we are saying she is not guilty of these two offences."
The jury has been discharged, and Miss Martin has asked the judge for a week to consider whether to seek a re-trial.