Allison Calhoun Dennis died in August after an extended illness

By Jodi Guglielmi
May 11, 2020 12:16 PM

Kathryn Dennis' Mother's Day celebration was bittersweet.

The holiday marked the first for the Southern Charm star without her mom, Allison Calhoun Dennis, who died in August after an extended illness. She was 59.

Dennis, 28, paid tribute to her mom on Sunday, sharing a throwback photo of her family to Instagram.

"Miss ya MoMo. Especially dancing with you in the kitchen, shaking our laffy taffy and furrrsure your pound cake. Still can’t find that recipe," she wrote. "You are missed. Those with good Mother relationships, those who have lost Mothers, those who never had a Mother, those with strained Mother relationships, Mothers with strained child relationships, Mothers who have lost children, those who long to be Mothers, those who have chosen not to be Mothers, those who are Mothers. Thinking of you. Happy Mother’s Day."

Dennis told PEOPLE in April that she was “incredibly close” with Allison, who was a descendant of the seventh U.S. vice president, John C. Calhoun.

“My mom’s my best friend,” Dennis said. “She stuck by me through so much. I don’t know what I would do without her.”

Kathryn Dennis and family
Kathryn Dennis/ Instagram

Allison was retired after working at Santee Cooper water service. She had previously battled cancer and moved in with her daughter during that time.

“She was sick for a year and a half and I was taking care of her,” Dennis told PEOPLE. “She’s since been living with me, essentially. It’s great to have her around, especially because she’s so good with the kids [Kathryn’s son St. Julien, 3, and daughter Kensie, 5]. She’s amazing. She’s the best mom I could ever hope for with everything.”

Kathryn Dennis/Instagram

Dennis, who is the mother to daughter Kensie, 6, and Saint, 4 with ex Thomas Ravenel, spent Mother's Day with her two children. The reality star documented their time together on social media, showing the trio playing outside and cuddling together at the end of the day.

"The best mother's Day present ever," she said in a video showing Saint resting his head on his mom's chest. "Having your little one fall asleep on you."