Have you submitted your application yet? If you put Shottery first, even if you don't get allocated a place on March 3rd you will automatically be put on their waiting list. Places are then allocated from the waiting list as and when they become available (up to Christmas I believe). But if you don't put them first, you'll then have to request this on March 3rd.
As for appeals, I don't really know, but I think you'd need to prove that your DD was academically best suited to a grammar rather than a high school (SATS predictions, school reports etc). I'm not sure they take family circumstances into account - its all about ability