Blackwall watches her quietly, letting her come to the idea on her own. It wouldn't do for him to push her on anything, let alone on the idea of getting a dog. Maybe it's more a Ferelden thing than a Marcher one, but he doesn't see why she shouldn't have one if she wants one. It might do her some good.

"Why shouldn't it be more than a thought?" he questions evenly. "A mabari would be a loyal animal and they travel as well as any horse. Better in some places. Besides, he can help you scout and fight. Protect the locals. All good reasons to have one."

Really, having another creature to look after might help her deal with the trauma that being the Herald seems to have dropped onto her shoulders. He doesn't envy her this weight, but he does want to try to lift it. If he can.