From what Mr Stimpson said when we met him, any dc from the the same primary school can be in the same form, if they want to be. My dd has said yes to this, as 2 other dc from her school are also going.
They will all get to meet each other on the 12th, as will us parents (as we all have to be there in time for the talk by the head of year 7 at 915.)
If you or any of the other parents want to say hi/ meet up for a coffee until we go back to pick our dc up, just give me a shout.
I've now lived in Slough for over 16 years so probably count as a local, lol.
Hopefully you will find some other parents on the day in a similar position to yourself and can help each other