。
She can speak Spanish well.
Literal
She [topic-は] skillfully Spanish [object-を] can-speak.
話せます is the polite potential form of 話す ('to speak'). スペイン語 follows the standard pattern for language names: [country/region] + 語. The sentence uses を rather than が with the potential form — both are acceptable, with を sounding slightly more formal or emphasizing the skill.