。
She was glad she'd met him.
Literal
She [topic-は] him [to-に] met-and glad [quotative-と] thought.
会う ('meet, encounter') takes its partner with に — ~に会う. The te-form 会って links cause/circumstance to the felt emotion. Quotative と + 思う makes 'thought (it was) glad' = 'felt glad.' This kind of internal-emotion-as-quoted-thought is a common Japanese pattern: ~と思う ('think that, feel that') reports both opinions and feelings.