I am planning to wait until age 70 to claim my social security benefits. My wife worked outside the home for a time before we started our family, but has not worked for a paycheck in many years. It turns out she's 3 credits short of the 40 required for her own benefit. We're planning to move and offer our current house for rent soon--is it possible to use that business in some way for her to get her 3 remaining credits? Thanks!