Sir Paul McCartney has introduced his daughter to rumoured new girlfriend Rosanna Arquette, according to reports. The actress met four-year-old Beatrice - his child with former model Heather Mills - on a visit to the Beatle's estate in East Sussex, England, leading to claims the pair have embarked on a serious relationship. A source tells British newspaper The Sun, "Of course (they are an item). It's on! Why would he take her to his country estate to meet his little girl? "He's checking her out. They've both told me." The couple was first pictured together in London last month (Nov07). Mills and MCCartney are currently locked in a bitter divorce battle which is yet to be resolved.