。
She was merely stating facts.
Literal
She [topic-は] facts [object-を] was-stating [to-pass-に] not-exceed.
~に過ぎない ('nothing more than, no more than, merely') is a fixed expression built from に + 過ぎる ('exceed, surpass') in negation — 'does not exceed [merely X].' Used to downplay or de-emphasize: 'it's nothing more than X.' The full frame is [clause / noun]に過ぎない. Combined with the past progressive 述べていた ('was stating'), the sentence frames her behavior as innocent, modest, or mitigating. 述べる is a formal verb for 'state, express, mention' — slightly more formal than 言う.