white-bread life

Jennifer WeinerのFly Away Homeを読んでいます。
"I'm on the New Jersey Turnpike. What's going on?" Sylvie settled more comfortably into the seat, readying herself for the soliloquy Ceil would doubtlessly deliver about New Jersey. Ceil hated suburbs and conformity and any place where people lived that wasn't the right neighborhoods of Paris or Manhattan, even though she, herself, was leading as white-bread a life as possible, with her ex-Cornhusker husband named Larry, her twins Dashiell and Clementine, and the granddaughter named Lincoln whom she carted to Little Mozard music class every Tuesday (the normalcy of that, she insisted, was leavened by the fact that her daughter was a lesbian, and that Suri Cruise had attended one of Lincoln's makeup class).
上に出てきた "white-bread" は文脈からすると平凡なと解釈できそうだがどうでしょうか？　辞書を見ます。
・Oxford English Dictionary: Blandly conventional in a way that is regarded as characteristic of the white middle classes.: inoffensive white-bread comedies
・Macmillan Dictionary: ordinary or traditional, used especially to refer to the behavior and values typical of white North Americans: white-bread tastes
・Dictionary.com: pertaining to or characteristic of the white middle class; bourgeois: a typical white-bread suburban neighborhood.
ちょっと違いましたね。平凡なニュアンスもちょっとあるようですが、白人の生活、嗜好、思考に大いに関係がある様です。