Kim Richards is feeling "strong" following her release from rehab.

The Real Housewives of Beverly Hills star visited a rehabilitation centre in December to treat alcohol abuse and other "serious issues".

Kim's sister Kyle Richards is impressed with how her sibling is faring following her release from the facility.

"She's strong right now," Kyle told E! Online at the signing of her new book Life Is Not a Reality Show at Barnes & Noble at the Grove in Los Angeles Thursday night. "We're taking every day day-by-day and just moving forward."

Kyle is elated with the bond that she and Kim have following her rehabilitation.

"We're the best we've been in a long time," Kyle shared. "I really feel like I have my sister back."

Kyle and her sister Kathy Hilton are happy to assist their sibling with anything Kim may need during this difficult period.

"Kathy and I are just there with her and supporting her and trying to keep her strong because anybody's who's gone through something like this knows it's very difficult... you need your family and friends to support you," Kyle explained.

Kim visited rehab several times in the past and almost died of alcohol poisoning years ago.

The mother-of-four is a former Disney actress, starring in several films in the 70s and 80s but faded into obscurity until her role in the hit reality show.