I have a premium Chess.com membership. Do Chess.com benefits apply to ChessKid too?
Unfortunately, no. While we're the same company, Chess.com and ChessKid.com are different websites, and the premium memberships operate separately.
Additionally, the signin details are also separate; usernames and passwords on Chess.com will not apply to ChessKid. You'll want to create a new account on ChessKid, but of course, you can attempt to get the same custom username (which will go through manual approval for safety reasons) and you can use your same email address.