Using Granny as Your Nanny?
Chat about expectations. There's no need to treat Grandma like an employee (spare her the staff handbook), but be up-front about things like expected hours and the daily routine.
Put her on the payroll! She might refuse pay, but you owe it to her to ask. If she says no, regularly acknowledge her work and compensate her in other ways -- say, with a trip or restaurant gift certificates.
Make sure she's still up to the task. Holding, feeding, and changing a baby is doable enough but soon your tot will be more active -- a lot more active! Agree to regroup in six months or so to see how things are going.