EXCLUSIVE: Kyle Richards Says 'RHOBH' Co-Stars Are Questioning 'Exactly How Sick' Yolanda Foster Is

During a one-on-one with ET this week, The Real Housewives of Beverly Hills star Kyle Richards revealed that Yolanda Foster's Lyme disease becomes a focal point in the show's sixth season.

Questions about the disease stem from Foster's 2012 diagnosis, which some of her co-stars have expressed doubts about.

WATCH: David Foster Says Wife Yolanda 'Is Doing the Best She Can' Battling Lyme Disease

"I think for a lot of people it's very confusing," Richards told ET. "A lot of the things she's gone through and the treatments she's done, for some of the cast members they were questioning exactly what she was doing and exactly how sick she was. It was not a good situation."

According to Richards, the ladies have their reasons.

"Some things came up that made some of the Housewives question exactly what was really going on," Richards teased, insisting that we would have to watch the upcoming season to find out the specifics.

WATCH: Kim Richards Back to Filming 'Real Housewives of Beverly Hills'

Richards was more open about her home, as she took us on a tour of her 7,000 square-foot Bel-Air mansion. The reality star and her husband, real estate agent Mauricio Umansky, just finished a $1.5 million renovation on their property, which Richards called her "dream home."

"It's a little big. It's deceiving," Richards said. "When you see the outside it looks like a cozy home, but it's seven bedrooms, eight bathrooms."

Before the renovations, Richards said the house was an "outdated '80s modern," which she didn't love, but was drawn to the "energy." To put their mark on the home, Richards and Umansky worked with their friend, designer Faye Reznick, to bring both their visions to life.

The Real Housewives of Beverly Hills returns to Bravo on Dec. 1 with Richards' sister Kim, who entered rehab for the fourth time in April after she was arrested at the Beverly Hills Hotel for public intoxication, also appearing.

WATCH: Kim Richards Getting the Help and Support She Needs

"My sister's doing really well," Richards said. "She needed this time to take of herself, and that's what she's done. She's in a good place, so we're happy."

Watch the video below for a look inside Richard's beautiful home.