You're browsing the GameFAQs Message Boards as a guest. Sign Up for free (or Log In if you already have an account) to be able to post messages, change how messages are displayed, and view media in posts.
"...useful, for example, if you need to change Trade Rules with the Queen of Cards and you sent her back to Balamb as advised before the Missile Base (make sure her Trade Rule is All before starting in the Garden). This is your only chance for quite some time to do this, so take care of it if you can.)"
I didn't send her back to Balalmb, and it seems like not having done so might put a halt on her side-quest for a little bit.