Her eyes focus on their hands for a long moment, before she looks up to meet his eyes.

"I - " She pauses, trying to find the right words to explain her thoughts. "I think...I think I could be happy here with you. But I...if it hadn't been suggested, I don't...I don't know if I'd have ever thought of marrying you." She gently squeezes his hand to stave off any immediate response. "And it's nothing to do with you. I think you're a good person, and I know you would have taken care of any woman who might have married you. I just...hadn't considered marry you before because...well, we're friends. It just...never really occurred to me."

Kind of like how it had never occurred to her that she could have married Aang until later.