From my research, it looks like we should take the train to Wimbledon station and the adults should use contactless payment but I should buy a paper ticket for my 13 year old so it will be 1/2 off and then at Wimbledon, buy her an Oyster card and have them add on the young visitor's discount? We'll be there 4 days. I would get the oyster from Gatwick but apparently, we can't get the young visitor added there?
Looks like we take Thameslink or Southern. Same price and route. Is there a difference between the two that I am missing? We arrive at Gatwick at 10:30am.
Thanks