。
Whenever she saw a spider, she'd let out a shriek.
Literal
She [topic-は] spider [object-を] see [whenever-と] always shrill-voice [object-を] raised.
The conditional ~と here is the 'whenever, every time' use — paired with いつも ('always'), it expresses a habitual reaction rather than a single event. クモ ('spider') is usually written in katakana in modern casual prose, with the kanji 蜘蛛 reserved for more formal or literary contexts; in folklore, a morning spider is said to bring good luck while an evening one is a bad omen. 金切り声 ('shrill scream, piercing cry') is a vivid idiomatic expression: 金 ('metal') + 切り声, evoking the high, ear-piercing sound of metal being cut — perfect for describing a startled scream. 声をあげる ('raise a voice, let out a cry') is the standard collocation for emitting a vocal sound. The verb is in past tense 上げた, despite the ongoing-habit reading — Japanese often uses past tense for habitual past behavior.