A woman was "laughing" about allegations that she assaulted the sister she is accused of killing.
Lynnette Greenop, 40, was said to have found the claims involving Sharon Greenop "funny".
A jury was told Sharon, who died in 2016, also remarked she did not want her sister "near her".
Lynette and Sharon's daughter Shayla, 20, deny murdering the mother at the home they shared in Troon, South Ayrshire.
It is claimed Sharon, 46, was assaulted on various occasions between 8 September and 10 November 2016.
'Laughing about it'
Chloe Craig, who was a friend of Shayla, often stayed overnight at the house.
She soon became aware Sharon was disabled and needed caring for.
Prosecutor Ashley Edwards QC asked the teenager about visits to the house in 2016.
Chloe, 19, claimed she spotted Sharon with a black eye but the mother said she got it from pulling a plug from a sink.
The witness recalled then having a conversation with Shayla about the injury.
She told the court Shayla "thought" Lynnette was responsible.
It was claimed Lynnette was "not bothered" that it may be known she allegedly hit Sharon.
The advocate depute asked Chloe what Lynnette's "demeanour" was like at the time.
She replied: "She was laughing about it."
Miss Edwards: "As well as laughing, was she giving any other impression?"
Chloe: "No, she just seemed to find it funny."
'Body behind door'
The teenager recalled another occasion when Sharon was in bed and she started crying.
Chloe told the jury: "She said she did not want to be there and did not want Lynnette near her."
A charity worker later told the trial he went to collect a couch from the Greenop house - and thought he spotted a dead body.
Mark Grant went with colleagues to the property in August 2016.
He told the court that when he pushed a bedroom door open and he noticed someone lying on the floor.
Mr Grant, 32, recalled: "I could not tell if it was male or female at the time.
"It looked like blood on top of the head.
"The person had a kind of hospital gown on.
"It was just five or six second I was in...glimpsed and back out."
He said he did not speak to the individual or see any movement.
Mr Grant helped collect the suite before revealing what he had seen to his supervisor.
The witness recalled: "I got in the van and said: 'It looks like someone is up there dead'.
"It was a nervous giggle at the time.
"The supervisor - I don't think - believed me."
Mr Grant said there had been a woman outside the house when they arrived but she did not look "suspicious" and that there had been no attempt to stop the men going upstairs.
The murder charge alleges Sharon was repeatedly struck with "object or objects" and had her neck compressed.
It is said injuries were also inflicted "by means unknown" and that there was a failure to obtain medical help.
Sharon is stated to have been so severely hurt that she died.
The two accused, who both live in Ayr, South Ayrshire, deny all charges.
The trial, before Lady Carmichael, continues.