Looking at booking a trip from darlington 16. 23 to Aberdeen a week today , if I book for 1 adult and 2 children £160 , but on the day my daughter doesn't want to go will the tickets still be valid with only been 2 of us ? As it has the group sign on ? In fact it looks cheaper booking for 3 of us then 2. I have a f and f railcard my daughter does have a disabled railcard if anybody can find it cheaper