。
She's almost never late to school.
Literal
[topic-は] rarely school [for-に] be-late thing-[topic-は] does-not-exist.
学校に遅刻する ('be late to school') uses に to mark the destination one is late to. The contrastive は in 遅刻することはない ('being late, that specifically does not happen') singles out tardiness from other potential failings. Japanese schools enforce strict punctuality — 朝礼 (morning assembly) typically begins at a fixed time, and homeroom teachers track lateness. This contributes to the punctuality habit that follows Japanese students into adult work life: trains pride themselves on minute-precision, business meetings start exactly on time.