Since Gilly was dead, there was little problem to pass Val as her sister. And since Val had married Harrion Karstark, she was no longer a simple "wildling'. And boy wasn't that a surprise, a lord wedding a spearwife. Although, after seeing Val in person, people nodded their heads in understanding - the reason why that marriage had happened was quite clear. Jon didn't mind much - while Val was respected, no swords or spears came with that match, so Karhold did not benefit politically. Not only that, but it weakened Karstark's ability to forge alliances in the future, as some of the lords would definitely have qualms about wedding their children to the Karstark progeny now.