You and your wife each have a separate account. You can't combine the two into one account. But each of you can redeem award travel for your wife/husband as well as for yourself. Having two accounts is much to your advantage. It would be advantageous to have an extra 50k miles in your wife's account.

Keeping both accounts active is not difficult, and does not require flights. Just use the credit cards and/or sign up for the dining programs, submit a profile, and dine in participatin restaurant every 18 months.