Why should she?

Showbiz - News - Bedingfield refuses to adopt US accent - Digital Spy

Natasha Bedingfield has insisted that she will not be drawn into adopting an American accent, despite living in the US for a year and a half. The singer refuses to follow in the footsteps of fellow artists such as Joss Stone, who has returned to Britain with a quasi US twang. Bedingfield claims she has so far withstood the pressures from various camps to adopt the local accent, and is adamant she will not attempt to sell records by pretending to be American in the States. “I haven’t picked up an accent, unlike other people, she confirms. “I was hardly going to come back with a full accent. I love my English one too much.”

And why should she? Particularly as Joss Stone’s was embarrassing as opposed to being authentic anyway.