Once you have purchased a Gift Membership, a tab will be added to your Account page from which you can view the status of all gifts you have purchased. Here’s an example of what that might look like:
Note that there is a link in the “Status” column for “Send Gift Email”. When you first purchased the gift membership, you would have sent such an email to the recipient. That email contains a link that allows the gift recipient to claim the gift and begin his or her membership. If you see that your gift recipient hasn’t claimed the gift after a period of time, you can resend that gift email as many times as you want from this screen.