Years ago I took a Suzuki piano teaching course. Although I only include selected elements of the method in my teaching, one belief I acquired is that when a young child takes lessons, the teacher is the guide one day a week, and parents are the guide the rest of the week.

I teach with a lot of precision in order to put my students on a path towards success. Young children who are just beginning to figure out how their bodies work while getting their first exposure to music cannot be expected to remember a lot of details when they return home from a lesson. For that reason I expect a parent to be at the lessons and to actively assist in practice when children are in kindergarten through most of elementary school. By the time a student reaches middle school, is still very helpful to have parents at lessons and at least nearby in practicing, but the students gradually assume more responsibility for their work. 

I will often have parents sit at the piano so that I can show them things directly; they can guide their children better if they have first-hand experience. 

As a parent myself, I fully understand the trials and tribulations of getting young children to practice. I suggest that parents who are considering piano lessons for their children try lessons for a month (you must have an instrument to practice on for that month). Try to establish a very regular and predictable practice time. If after the month, you decide to continue, commit yourself to regular lessons for a minimum of two years. The reason this is important is that there will be ups and downs in the process. Children learn a great deal about the value of perseverance and the joy of music by working through challenges to make new discoveries.