She died in a two-vehicle collision on Thursday morning at the Woodgreen junction on the main A26 dual-carriageway between Antrim and Ballymena, a short distance from her home.
The crash happened around 9.30am and there was dense fog in the area at the time.
Karla was on a day off from work and was on her way to visit her mum.
Her heartbroken husband David said she was adored by her pupils in Sunday School, and also at her job with Country Treasures Daycare in Randalstown.
David said: "She was the best wife I could ever want, she was a devoted Christian, and she just loved working with children.
"She dedicated her life to children and to helping others.
"Karla was unique.
"You can think of the words 'superstar', 'amazing' or 'one in a million' - they all describe her.
"She was just perfect.
"She would have done anything for anyone.
"Karla would rather have done things for other people than herself."
David (26) revealed how he held his wife's hand during her final hours in the intensive care unit of Antrim Area Hospital.
And he said he had been drawing strength from his faith and the support from friends and family since the tragedy.
"We were so involved in Ballee Baptist Church," he said.
"I know Karla is in Heaven, but I feel so lonely she is not with me."
Karla's sister in law said she will be "missed beyond measure".
In a Facebook post on her Cranberrylime craft giftshop business she posted a message.
She said: "Karla was a sister to Ruth and I, it was always the three of us. We will miss her beyond measure."
Pastor Lawrence Kennedy from the church spent time with the family before and following Karla's passing in hospital.
He said: "David and Karla were in charge of our children's meetings, our Good News clubs. The folk just loved her and they are devastated at the tragedy."
Karla was an assistant manager at Country Treasures Daycare, where owner Kieran McCavana said: "We thought the world of Karla. She didn't just work for us - she was part of the family. Everyone is devastated at her loss. She was extremely thoughtful.
"She was so conscientiousness and she was just one in a million and we will miss her deeply.
"She worked with us for over three years. Her and my wife know each other exceptionally well. We are all a bit numb. We are closed on Monday for the funeral. Staff are too devastated to work."