。
She headed toward the rice paddies.
Literal
She [topic-は] rice-paddies [possessive-の] direction [toward-に] advanced.
田んぼ ('rice paddy') is the everyday word for wet rice fields — a core element of the Japanese rural landscape. ~の方に ('toward the direction of') is the standard way to express approximate direction. 進む ('to advance/proceed') is more deliberate than 行く, suggesting purposeful movement.