。
She glanced at me.
Literal
She [topic-は] me [object-を] briefly looked-at.
ちらりと is a state mimetic (擬態語) for a brief, fleeting moment — most commonly used for a quick glance, but also a brief glimpse, a fleeting thought, or a momentary sound. The variants ちらり, ちらりと, ちらっと all describe the same flash of momentariness; the と (or っと) gives it adverbial form. Pairs naturally with 見る for 'glance,' with 思う for 'briefly think,' or with 聞こえる for 'briefly catch (the sound of).' A precision Japanese has for the texture of brief perception that English handles with a generic 'glance' or 'flicker.'