Bit late, was waiting for other half to come home from work
I apologise also, not difficult I can assure you. He says if they get on with no pass some drivers may let them travel because it is easier than having abuse hurled at them :(. If they even look older than 10 travelling with an adult they must also pay the full fare
However, they pay the full adult fare (the fare is the same for children and adults alike) with no pass
Apparently, as well, TFL do not do children staff passes only spouse ones - so looks like I'll have to start paying for my daughter in 2 years time