。
She can speak French.
Literal
She [topic-は] French [subject-が] can-speak.
The simplest possible 'she can speak French,' but with one twist worth noting: が (not を) marks the object of the potential verb 話せる. This が-marking is a recurring quirk of Japanese potentials — the thing one is able to do appears with が rather than を, since the potential effectively turns the predicate into a state of capability. Compare: フランス語を話す (action — 'speaks French') vs フランス語が話せる (capability — 'is able to speak French'). Beginners often miss this and overuse を with potentials.