Sharon Osbourne has hailed her daughter Kelly Osbourne as her ''rock'' in the past few months.

The 60-year-old TV presenter - who has reportedly been living separately from Ozzy Osbourne, her husband of 30 years, who admitted last week he has been drinking and taking drugs for the last year-and-a-half after relapsing - has heaped praise on the 'Fashion Police' host for ''being there'' for her.

A friend told the Daily Star newspaper: ''She cannot praise Kelly enough for being there for the past few months, especially as Ozzy has been so troubled. She has been her rock.''

Sharon - who battled colon cancer in 2002 - was also grateful for the 28-year-old star's support following her preventative double mastectomy operation last year after she underwent an advanced DNA ''geno'' screening which revealed she was at risk of contracting breast cancer.

Speaking on an advert for Fashion Targets Breast Cancer campaign - which she is supporting alongside Kelly, model Daisy Lowe and her designer mother Pearl - about why she went under the knife, the 'Talk' star said: ''It just made sense to me. I want to ensure I'm there for my family. It is a cause that is close to my heart.''

Kelly added: ''I'm so happy to be in this with my mum - she is the most important woman in my life.''