Still a work in progress. Kim Richards opened up about her tumultuous relationship with her sister Kyle Richards during a special one-on-one interview with Andy Cohen for Watch What Happens Live on Tuesday, March 8.

The Real Housewives of Beverly Hills stars recently made amends, as seen on the Bravo series last year.

"It was hard. It was very difficult," Kim, 51, told WWHL host Cohen. "For myself, I have to take the hurt — the hurt won't ever really go away. But there's certain things that she had done towards me that I personally have to, things that happened between us, that I have to put aside if I want to move forward."

"I couldn't return her phone calls for a while," the former child star, who has struggled with sobriety, continued. "She called and reached out to me and I just wasn't ready."

Several factors played into the siblings' long estrangement. Perhaps most notably, Kim's dog Kingsley bit Kyle's daughter Alexia in November 2014, and Kim often sided with Brandi Glanville over Kyle.

"Kim takes issue with Kyle because she feels as if Kyle has thrown her under the bus too many times," a source told Us Weekly in April 2015.

Kim's relationship with Yolanda Foster has also been featured on RHOBH. Kim has been in Foster's corner as she fights Lyme disease, even though other costars like Lisa Rinna have accused Foster of being manipulative.

"I've watched my friend suffer for years now," Kim told Cohen. "It's very painful to watch her. She's weak, she's in pain, she's suffered, clearly."

For more with Kim, watch her one-on-one WWHL appearance in the video above.

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