A common response to someone expressing a phobia is listing all the rational reasons they shouldn't be afraid, which is generally well intentioned, but are likely things the person already knows, which is just frustrating.
I speak from first-hand experience. I have fears and impulses I know to be irrational even though I know exactly why they're irrational. Someone responding with "oh, but there's no reason to be afraid, here's why" is a "stay calm and count to 10" moment.
I'm confident saying there's nothing in the archives that contradict this, since I don't recall ever even drawing a dog for anything that's canon in EGS (which makes them a bit overdue, I'd say).
In any case, I like that Grace finds big dogs scary. One might be thinking what Sarah is likely thinking, which is "but Grace can talk to animals". To that I counter "I can talk to people, and some of them are still scary".