Make sure you’re logged into the exact Steam account the gift card was sent to. Sometimes if you’re logged into the browser with a different account, the link just dumps you into the inventory without showing anything. It also helps to try opening the link directly in the Steam client instead of a browser.

If it still doesn’t show up, ask your wife to check her purchase history in Steam — the order should say “Gift Card sent to [your account name].” If the recipient email or account name was entered incorrectly, the card might have gone to the wrong account.

If everything matches and it still isn’t appearing, the next step is to contact Steam Support under “Purchases > Steam Gift Cards.” They can trace the transaction and apply the balance manually if something glitched.

Also to add, if your wife doesn't have a steam account and brought the gift card as a guest, then it will take a couple of days for the funds to go into your account.