、。
Looking pressed for time, she repeatedly stole glances at the wall clock.
Literal
She [topic-は] time [by-に] is-being-pressed appearance [in-で], frequently wall [possessive-の] clock [object-を] briefly looked-at.
Several elegant pieces stack here. 時間に迫られている is the passive of 迫る ('press, close in') with 時間 marked by に as the agent — 'pressed by time.' The resulting clause modifies 様子 ('appearance, look'), with で marking circumstance — 'with the look of being pressed for time.' しばしば ('often, frequently') is a slightly literary adverb. ちらりと (or ちらっと) is a 擬態語 — a state mimetic for a fleeting glance, captured in English as 'glance, peek.' 壁の時計 ('wall clock') reinforces the visual scene.