Lyanna has noticeably vanished from the feast, clearly upset over something more than just Robert Baratheon. She'd looked just a breath away from fighting Ned, in front of the royal delegation and everyone else gathered in Winterfell's great hall, though only her own son would've noticed that.

Jon will find her in the crypts, in front of her brother Brandon's statue.

"The South is no place for a Stark," she says when her son comes, her voice lined with steel yet also close to breaking. "Robert has asked Ned to be his Hand, and..." She shakes her head repeatedly, as if that would change her other brother's mind.