Ishani, the local authority can't offer you a place until they know you are moving! You have to be able to show it on paper; either a rental contract with a start date or a solicitors letter with a completion date if buying.
They can't offer you until they know this otherwise people would just contact the local authority and say they're moving when they're not, just to try to get their kids into a school that's not the closest.
When you apply mid-year, they simply give you the spots they have available and if there is more than one, they let you choose. You can also be put on the continuing interest list for the school of your choice and basically wait until a space becomes available for you.
This is the the problem we are now faced with when moving (in three weeks) for my DS1 who will be in year 2 in September.
He will simply be given a space at a school in the area and if you don't like it, you either pay to go private or you home ed.
We are therefore looking into areas with mostly good schools so even if it's not the closest, he will still be in a decent school. And then when my DS2 gets a place, which will be able to select (choice of 3) he will go to the top of the list as a sibling if we want to transfer him.
In answer to your question, I don't know if she will do well or not. There are so many factors involved in a child's performance at school and a good ofsted is not the sole determining factor here.