The 32-year-old socialite - who is married to the Good Charlotte rocker's twin brother Joel Madden - ''approves'' of the couple's new relationship and admitted she was the one who got them together.
Asked on 'Watch What Happens Live' if she set them up, she said: ''Yes. I'm going to take responsibility for everything!''
Nicole - who has children Harlow, six, and Sparrow, four, with Joel - is delighted her brother-in-law has found happiness with the 'Sex Tape' actress in recent months.
She added: ''I approve of anything that's going to make Benj happy.
''I am a devoted sister in law. I'm happy for anyone who is happy, and I want everyone to be surrounded with love.''
It was previously claimed that 35-year-old Benji is ''madly in love'' with the 41-year-old actress, but she doesn't want to rush into anything serious.
A source said recently: ''Benji is madly in love with Cameron, but she wants to take it slow -- he isn't her usual type. He has dated a lot of Nicole's friends in the past but Nicole really wants this one to work.''
We explore the musical culture of Camden as Madness and Amy Winehouse receive their stones on the Music Walk of Fame.
The Quarterhouse, and Melting Vinyl, played host to two inspired performances in Folkestone on the first evening of March.