Reunited! Kim Richards Celebrates Her Birthday With Brandi Glanville and Yolanda Foster

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BFFs!

Although Kim Richards won't be returning for the upcoming season of The Real Housewives of Beverly Hills, she still has loyal friends when it comes to her former co-stars Brandi Glanville and Yolanda Foster.

The 51-year-old reality star celebrated her recent birthday with her two gal pals, and Instagrammed about it on Thursday.

"I had a great birthday lunch with with my my girls.... xoxo @yolandahfoster @thebrandiglanville love you," Kim wrote.

WATCH: EXCLUSIVE -- Kim Richards on New Determination to Stay Sober: 'Relapsing Was Very Hard For Me'

Brandi also tweeted out this cute selfie of the ladies.

"Birthday lunch for my friend @KimRichards11 with the strong & Amazing @YolandaHFoster #realfriends," the 42-year-old star wrote.

Kim actually turned 51 on Saturday, Sept. 19., and spent the day with her sister, Kyle Richards, and her daughters, Whitney and Brooke. It's nice to see Kim and Kylie close again, especially after they had a massive falling out during last season of RHOBH -- much of which was over concerns about Kim's sobriety.

Kim entered rehab for the fourth time in April, after she was arrested on April 16 at the Beverly Hills Hotel. She was charged with public intoxication, trespassing, resisting arrest and battery of a police officer, and issued a citation for a misdemeanor following an incident.

"I love sobriety," Richards told ET's Nischelle Turner during an exclusive sit-down in July. "I've always loved sobriety, and relapsing was very hard for me. It was not easy. I have to say -- don't take this wrong -- but I really wanted to go to treatment because I needed a break from what I was going through at home."

"Monty, my ex-husband, is very sick and my son wasn't well," she further explained. "And I had to give away my dog, and I wasn't talking to my sister [Kyle]."

Earlier this month, Brandi also chatted with ET about supporting Kim.

"It's hard, because, you know, I'm a friend, [but] I'm not, you know, a sober companion," Brandi admitted. "Obviously, I'm not a coach. You know, I'm there for her as a friend. I will always take her calls, and that's really all I can say about it right now."

WATCH: EXCLUSIVE -- Kim Richards on 'Real Housewives' Drama: Lisa Vanderpump Is 'Phony'

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