Well, maybe she means some time in the future.
Doesn't have to mean in a couple of months or some thing.
I'd like to say, while there wasn't really any thing shippy between DawnxAsh, the BunaryxPikachu storyline was supposed to compare. So maybe Dawn likes Ash too?
And besides, this was suppsed to really be a closer to Kenny's storyline now.
She said they were just friends in the letter, closing Penguineshipping in the end.