In custody since his arrest 12 months after the death, the now 60-year-old Beckett faces a life sentence with a minimum term of 25 years if found guilty.
A friend of the Becketts from Westlock, Albert, where the couple lived, told the jury on Tuesday she never saw any tension between the couple, the Kelowna Daily Courier reported.
Anita Leigh said she came to know Laura in September 2007 when her eldest son was in a class Ms Letts-Beckett taught at Dapp Elementary, and she met Peter the following year.
"[They were] like any normal couple, happy to have people around, just loving life," Ms Leigh told Justice Alison Beames and the jury, when questioned by defence counsel Marilyn Sandford. "I always saw a couple who cared very deeply for each other."
Between 2008 and 2010, Ms Leigh and her family would often get together with the Becketts, including at Forfar Park in Alberta, where the Becketts often went camping.
In that time, Leigh said she never noticed any changes in their relationship and added: "They enjoyed each other's company. They were a loving couple."
The jury has previously heard the Becketts, who met in New Zealand when Beckett was running Unimog Adventures, a Cape Kidnappers day-excursion tour operation out of Napier and who married in Canada, separated in 2007.
When they got back together after a few months Ms Letts-Beckett became estranged from her family.
Ms Leigh told the court that Beckett stayed in his motorhome on the witness's property for about six weeks.
"He was an inconsolable man," she said.
"He would cry all the time; he would talk about times with Laura, about how much he missed her.
"I saw a man go from being this outgoing, gregarious man to being just a shell."
In cross-examination, prosecutor Mr Goulet asked Ms Leigh about a conversation she had with Ms Letts-Beckett about falling into water.
"She said to you that she always thought Peter would save her?" Mr Goulet asked.
"Yes," said Ms Leigh.
"That's because 'he'd always been on the water and he knew a great deal about the water?" Mr Goulet continued.
Ms Leigh: "That's correct."
The trial, which started on August 21, is expected to end early next week.