I have a daughter in year 10 at WoK she has friends from many areas such as Oxted and Wadhurst who managed to get in. It obviously depends each year but as there are 3 extra classes ( 90 places) at Sevenoaks too she should be in with a good chance.
Interestingly some of the OC children get to school quicker than the more local with a good train service. Obviously her friends would be spread wider but as long as you don't mind being a taxi service for all their sleepovers it won't be a problem
I have a little one who'll (hopefully) be starting next September, it really is a very good, supportive and nurturing school. Good Luck and well done to your DD for passing, thats the tricky bit.