Multiple accounts and earnings question

Hi all,

I’m thinking about setting up a second account for my nephew and teaching him to build themes as we go, but it will be under my name and with the same account for withdrawing ( I believe this is allowed, please correct me if not )

At the moment for a $59 sale I actually get around £29. Can anyone tell me what that would change to for a new account ? I looked online but everything i found was pretty outdated.