。
She may have gotten lost.
Literal
She [topic-は] road [to-に] got-lost [might-かもしれない].
A clean example of ~かもしれない expressing possibility about a past event. Attached to the past tense 迷った, it becomes speculation about something that may have already happened — 'she might have gotten lost.' The construction is the same regardless of tense: the tense sits inside the verb, and かもしれない wraps the whole proposition in uncertainty.