Sereda Aeducan had heard the tale of the fall of Erebor; Gandalf had not wanted her to travel with her Middle-Earth kin being ignorant of the suffering they'd endured. She'd heard it in excruciating detail, and a part of her did wonder how Gandalf knew so much about it without ever having been there himself, but she was so enraptured by heart ache and sympathy that she didn't question it.
She absorbed every detail to a point where she felt as though she was there – she could feel the heat of Smaug's fire, feeling agony as walls crumbled and lives were lost. Looking back on it now, it was clear that she'd been projecting – the dwarves of Middle-Earth losing the glory that was Erebor made losing Orzammar to the darkspawn seem almost inevitable. It had frustrated her to know that nothing she'd done as a Grey Warden would prevent her beloved city from falling some day.
But if she could help Thorin Oakenshield and the others take back their home, perhaps there would be hope for future surface dwarves – or even other Grey Wardens – in Ferelden to reclaim Orzammar should it ever fall into the hands of the darkspawn.
The exiled princess fought for her dwarven companions, of course, but she also fought for hope for her own home as well.
Despite the vividness of Gandalf's story of Erebor, it was an entirely different experience to hear of the recollection from Balin of the Mines of Moria being reclaimed. Thorin watching his grandfather's army falling in battle with the orcs (who were eerily similar to darkspawn, from what she could tell) only to have Thror be slain by a pale orc by the name of Azog the Defiler. With his grandfather dead and his father missing, the army was scattered, leaderless… until Thorin, wielding an oaken branch as a shield, cut the sword arm off of Azog, and turned the tide of battle, emerging victorious despite the heavy losses.
After that, she couldn't help but look at Thorin with the utmost respect… and maybe a little longing.
Just a little.