Hello everyone!

About a year ago I gave my sister this game as a gift. The laptop she had then broke and she got a new one. She asked me how to get the game on her new laptop and I told her to go to her email and look for the download there. She found the e-mail and tried to get the code but she got a message saying it was already redeemed.

How can my sister get the game on her new laptop?

If she has redeemed the game, then ask her to log into her GOG.com account and check her account by clicking Account. The game will almost certainly be there.

I would assume that when redeeming a gift code, you are required to register an account, in the same way that Steam Codes work. So it will probably be tied to her account.