Yes, your wife can use your airline miles, but the process depends on the specific airline's policy. Most frequent flyer programs allow you to book a flight for someone else directly from your account; you simply enter her name as the passenger and pay with your miles. Some airlines, like British Airways or JetBlue, offer "Family Accounts" or "Pooling," which let household members combine their miles into a single pot for easier redemption. Alternatively, you can "transfer" miles to her account, but this is almost always a poor financial decision as airlines typically charge a hefty fee per mile transferred, often negating the value of the rewards. In some specific programs like Singapore Airlines' KrisFlyer, you must first add her as a "Redemption Nominee" before you can book for her. Generally, the most efficient way to share the wealth is to book the ticket yourself using your login and simply put her details in the traveler information section.