Since I messed up on the Humble Bundle, I decided to give my extra keys to my cousin.
As it turns out, you can't re-gift gifted Humble Bundle keys. The only thing you can do with them is "Claim". Also, either I'm very stupid or I can't see the gifted games on her Humble Bundle profile. The only way to access their pages (which you wouldn't need to do, because they're already redeemed on Steam) is to directly access their "key" URLs.
Good that you can't re-gift them, but sadly you can't have them show up on your page, for better inventory of stuff. Oh well.