Paying for 6 year old on TfL

[BigRedBoat]

Hoping and London Mumsnetters can advise, I've looked on the TfL website but can't see an obvious answer. I usually use contactless payment on the underground but my dd has been under 5 when we've been before, she's now 6 so needs to pay but I can't work out if I can pay for both of us with the same card by touching in and out at stations? I'm presuming I can't and will need to get her a travel card but just wanted to check I'm not missing anything obvious.

Dobble some routes that Overground share with other trains aren't TFL though. The Croydon - London bridge line has both Overground and Southern trains. Once you have 'beeped' into the station you could get on either train and when you beep at the other end the system doesn't know if you caught an Overground train or a Southern. That's why I never quite figured out if Overground was free or not.

Thank you everyone, we will just be using the underground and possibly a bus so we should be ok.

@ArtemisiaGentle slightly different for bus, a child doesn’t have to be with a fare paying adult , they can travel unaccompanied up to 11years old...

BigRedBoat avoid the confusion of South London and you'll be fine