Sarah Cotton was back on the witness stand Wednesday in the trial of her ex-partner who is accused of murdering their two young daughters in Oak Bay in 2017.

Cotton began her chilling testimony Monday at the trial of Andrew Berry, who stands accused of second-degree murder in the deaths of four-year-old Aubrey and six-year-old Chloe.

The girls' bodies were found in Berry's Oak Bay apartment on Christmas Day 2017. He has pleaded not guilty to the charges.

On Wednesday morning Cotton described her Christmas morning the day her daughters were found dead. She told the jury she texted and spoke with family and friends on the phone, and prepared stockings and gifts under the tree for her girls.

Andrew Berry was supposed to drop their daughters off at her house at noon. By 2 p.m. that day, they still hadn’t arrived. Cotton was waiting at her home for Berry’s parents to arrive for Christmas dinner, and after they arrived at 2 p.m., she went to Berry’s apartment to look for the girls.

Cotton became tearful telling the jury she never looked inside the apartment’s windows when she knocked on them.

“I assumed the girls weren’t there. I couldn’t hear the girls’ voices. If they were there, I would have heard them," she said.

She testified that when she didn’t get a response from knocking on the apartment windows, she and Berry’s mother searched various parks for the girls.

They went to Windsor Park, the Oak Bay Recreation Centre, Willows Beach, Cattle Point, Beacon Hill Park and the Cedar Hill Recreation Centre.

When Berry's lawyer challenged Cotton's testimony about her seeing toys in the snow behind Berry's apartment, she gave an emotional response.

"My children died on Christmas Day, so my memory about the snow toys may not be perfect," she said, adding she was focused on getting her children back alive.

Later, there was a heated exchange when Cotton was questioned by Berry's lawyer, Kevin McCullough, about which windows she knocked on at his apartment when she was looking for her daughters.

"Again, my children died on Christmas Day," Cotton responded.

"Mr. Berry's children died on Christmas Day, as well, Ms. Cotton," McCullough retorted.

The exchange left Cotton looking stunned and tearful.

Testimony concluded Wednesday with Cotton admitting she had written a note in February 2017, after Berry's living room window had been smashed, an incident she thought might be linked to gambling debts.

The note read: "I just hope my kids are okay if he is involved with bad people."

McCullough finished his cross-examination of Cotton on Wednesday. Crown counsel is expected to have a few more questions during a redirect examination Thursday morning.