First off, I've edited the "name" out of your post to protect the privacy of your girlfriend. If you need to, you can use their summoner name. Never use the actual account name as it could put that user at risk.
Make sure she checks all folders in her email. Depending on what email service she uses, the email could end up in something other than the standard inbox, which means it might be something she may have missed. I suggest giving it another try, and waiting for a short period of time before checking the email. It occasionally takes a bit of time for things to go through the system.
If that doesn't work, and she's unable to log onto the forums, she can either make a new account and make a post in Help & Support or submit a ticket to Riot Support. It's also possible to talk to our NA player support through our Moderation Discord Server.
All that being said, this is the wrong sub-board for these types of questions, so I'll be locking this discussion. If you have further technical questions, please direct them to the Help & Support sub-board.
If you have any questions or concerns regarding this moderator action, please visit us in the Moderation Discord Server. If you'd like to leave us feedback on our moderation or the boards in general, please make a thread in the "Discuss The Boards" sub-board.