Brian Wilson "is doing great" amid his ongoing health issues

Carnie told 'Entertainment Tonight': "He is doing great! He is doing great.

"Everyday he is in physical therapy. I'm cooking for him, he's spending a lot of time with his children now, his family."

Wendy is similarly optimistic about the situation.

She shared: "I think he's doing really good under the circumstances that he's going through right now.

"But, you know, he's a survivor. That's my dad. He's very tough, a very strong person."

Brian's health troubles are discussed in a new Disney documentary about The Beach Boys.

Carnie admitted that she feels proud of her dad's musical legacy.

She said: "You know, it's contagious. The Beach Boys music and spirit has always been contagious."

Meanwhile, Bruce Johnston recently revealed that The Beach Boys want to "do some music therapy" with Brian.

The 81-year-old star would still love to "bust a hit" with his former bandmate.

Bruce told The Times newspaper: "We should do some music therapy with Brian. He can't bust a move, but he might just bust a hit."

Despite Brian's poor health, Mike Love is convinced that his musical talents can still shine through.

Mike said: "As long as he is alive, Brian will be able to sit at the piano and do what he does.

"He has medical supervision, he communicates with his daughters Carnie and Wendy, and you know what? We lost Dennis [Wilson] in 1983, Carl [Wilson] in 1998, and somehow the music has lasted.

"When Brian and I do get together, it really is love and harmony. And we wouldn't have done the Beach Boys without each other."