Kathy Hilton Reveals Why She Feels 'Blessed' to Appear on 'RHOBH' With Sister Kyle Richards

Kathy Hilton is glowing with gratitude!

The matriarch became a fan-favorite "friend of" on The Real Housewives of Beverly Hills with her hilarious quips and authentic sense of self. Despite the drama of the hit series, she's just happy to spend quality time with her sister Kyle Richards.

The reality star chats exclusively with OK! about working with her sibling on the Bravo show, being a grandmother to Paris Hilton and Nicky Hilton's kiddos and her ultimate beauty secrets with the help of NAD+ boosting.

"I love them. We have a great time together — we laugh a lot!" Kathy spills about her fellow cast members. "I really enjoy the camaraderie and have been blessed to get to know each one of them. Spending time with my sister is the cherry on top of the cake."

When she's not hanging out with her girlfriends, the I Want To Be a Hilton alum spends quality time with her family, who keep her "grounded." Kathy is a grandmother to Paris' two kids, London and Phoenix, Nicky's daughters, Lily-Grace, Theodora, and son, Chasen, and Barron Hilton's kids, Milou, Caspian and Apollo.

"I have eight beautiful grandchildren. It’s been so much fun to start sharing our family traditions around birthdays and holidays," she says. "We had beautiful Bauble Christmas stockings made for each of them this year and seeing them filled brought me to tears. I love when the older ones FaceTime me and tell me about their days and the younger ones giggle when they see me. Watching my children with their children and seeing what great parents they are brings me so much joy."

While she may be a grandmother, Kathy looks as youthful as ever. "I drink a lot of water. I have a bottle of Saratoga Spring Water on my bedside table, my bathroom vanity, my desk and in my car — beauty starts from the inside out, so keeping hydrated throughout the day is key! I mix the sparkling water with POM juice to get the extra bang of antioxidants and it's super refreshing," she explains.

"Another non-negotiable in my routine is Tru Niagen. It’s one of my go-to supplements that boosts NAD+ levels, which decline with age. It helps support cellular energy production to enhance my skin, nails and overall energy. It’s an essential part of maintaining my glow and feeling vibrant every day. Beauty truly starts at the cellular level and Tru Niagen helps me feel and look my best!" the blonde beauty adds.

"I love a sheet mask — Knesko makes some of my favorites and I go through their eye masks like crazy," Kathy reveals. "I am obsessed with RéVive’s neck renewal line — I slather the serum on in the morning and the cream at night. I use a self-tanner to give a nice glow. I love this Australian brand, Sontse — it’s a great mousse. The Aussies know their way around sunless skincare!"

The mother-of-four is also a huge fan of NAD+ treatment, which helps slow age-related decline by boosting metabolic functions and cellular energy. "I heard about NAD about two years ago. I was connected to Tru Niagen, and it's been a love affair ever since!" she notes. "I have more energy, my hair and nails are stronger, and my skin has never looked better. I can’t live without it."