Celebrant Patsy Mountford paid respect to the "dearly beloved mum, mother-in-law, nanna, and sister" who was "taken too soon."
She said: "Lesley's tragic death has been a shock for us all - no more so than for her children; Sharon, Louise, Nicky, and Don, and their families.
"But we're not going to dwell on this tragedy. This was a wonderful woman who brought strength and light to her family."
She described the mother-of-four as "fun-loving, caring, and hard-working" and someone who would "go that extra mile to help you."
The celebrant alluded to her long-standing relationship with Mr Campbell.
"Her marriage faltered after 14 years and Lesley brought up her family single-handedly, and was extremely proud of them.
"For the last 25 years, Lesley shared a life with Don Campbell - so that was also 25 years of her children's life, which had a great impact on them."
Her son-in-law Allan Hewison recalled some of the lighter moments that the family shared with her.
He spoke of the "city girl" who took to Balclutha farm life remarkably well, "especially for a person who once asked if black sheep had different coloured meat to white sheep."
Her flower-laden coffin was carried out of the chapel by family members.
A funeral for Mr Campbell, a former farmer from Balclutha, was held at Harewood Crematorium last Saturday.
A police investigation is ongoing but post-mortems found the couple died after suffering single gunshot wounds.
