Practice should reflect age and level. Five to ten minutes of practice at a time for a very young beginner is usually good. For those starting out regardless of age, five to ten minutes per day, moving to two sessions per day of that duration, is recommended to gradually build both concentration and engagement.
Tag: encouraging children to practice properly
Practice part 2: It’s not personal!
A useful post on goal-oriented practice from the head of music at Monkton Combe School Practice part 2: It's not personal!
A Piano Teacher Writes... 