。
She might be able to answer the question.
Literal
She [topic-は] that question [target-に] answer [nominalized-こと-が] able-to-do might.
A textbook stack of two important grammar pieces. ~ことができる ('be able to') turns the verb 答える into an ability statement, framing capability rather than action: 'is in a state of being able to answer.' ~かもしれない ('might / it's possible that') then adds speculative uncertainty on top. The に on 質問 marks the target of the answering. Together the structure gives a hedged probability claim — useful when speakers want to suggest capability without overcommitting.