WASHINGTON (AP) — In a battle between the nation's second-largest bank and a part-time nanny with $2,200 to her name, the nanny scored a clear victory.Twenty-two-year-old Molly Katchpole started an online petition after Bank of America announced plans to charge debit card users a $5 monthly fee. One month and 300,000 electronic signatures later, Bank of America backed down.Katchpole is a Rhode Island native who lives in Washington. In addition to working as a nanny, she does freelance work for a political communications firm. She describes herself as a progressive and says she stands in solidarity with the Occupy Wall Street movement.She switched to another bank because of the fee. But she says she started the petition because not everyone has that option.