NEWPORT NEWS, Va. (AP) – A federal jury has convicted a Virginia woman on fraud and tax charges after prosecutors said she charged over a half-million dollars on her boss’s credit cards. Sherea Darnell is a former manager at a Williamsburg eye care center.  Prosecutors say she used the doctor’s credit cards to charge some $514,000 in personal transactions, including her son’s preschool tuition. The jury heard from prosecutors that she also took over $90,000 in cash advances from the credit cards, using it to hire maid services and buy clothing and airline tickets. Authorities say that after her resignation from the eye center, Darnell continued to use her boss’s cards until the doctor finally discovered the fraud. Darnell faces a maximum penalty of 30 years. Sentencing is set for October.