The Southern Charm cast member's mother passed away this week at the age of 59.

Kathryn Dennis' mother, Allison Calhoun Dennis, has passed away, The Daily Dish has confirmed. She was 59.

Allison passed away on Wednesday, August 7 after "an extended illness," PEOPLE reports. In addition to Kathryn, Allison is survived by her husband, Luke Dennis, and her son, Luke Dennis Jr.

The Dial-Murray Funeral Home in Moncks Corner, South Carolina has posted an online obituary for Allison.

Kathryn opened up to PEOPLE in April about how "incredibly close" she was to her mother, who was a descendant of the seventh vice president of the United States, John C. Calhoun. “My mom’s my best friend,” she said. “She stuck by me through so much. I don’t know what I would do without her.”

Kathryn's mother moved in with her during a past battle with cancer. “She was sick for a year and a half and I was taking care of her,” Kathryn 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. She’s amazing. She’s the best mom I could ever hope for with everything.”