It says what to do on the link from Bucks - they need to accept your move before your address can be used.
"If you move after you have applied,
you must give us evidence of this.For the first round of allocations you need to provide evidence to show that you have moved and are already living in your new home by 31 October 2018 so we can use your new address when we consider your school preferences.
Academies, together with Foundation, Free and Voluntary-Aided schools, and schools in other areas may have different deadlines so check their rules carefully. At the moment, the only school in Buckinghamshire with different moving deadlines is Dr Challoner's Grammar School.
If you are living abroad and are returning to a property in the UK, we will need to use the address that you are currently living at, unless you can provide evidence to show that you will be resident in our area by 31 October 2018.
If you move after the date given above, we will use your new address for later rounds of allocations, once we have accepted it. Please see evidence deadlines if you move after these dates. We use the address where you are living on 31 October 2018 for the first round of allocations on 1 March 2019. If you have only recently moved to this address you will need to provide the evidence before we will accept your new address.
If you move from the address on your application after 31 October 2018, you must tell us and provide evidence to confirm your move. However, we will use your old address for the first round."
The dates mentioned are here:
https://www.buckscc.gov.uk/services/edu ... on-rounds/"For the second round of allocations we will include:
* applications considered on National Offer Day where a place could not be offered and the child is on a waiting list
* new applications received between 1 January and 15 March 2019 which may include applications from families who have provided evidence to confirm they have moved into the area by the deadline of 1 March.
We will also change the address for school place application purposes
for families that moved after the October deadlines, but by 1 March 2019, and provided sufficient evidence to confirm this." So if you have moved and convinced them the move is genuine then the second round allocations will include your daughter. Of course DCHS will only be used if she qualifies.