Normal Sleeping Habits for Toddlers

My granddaughter is 26 months old. She’s cheerful, physically active and developing normally language-wise. She attends a nursery school during and interacts well with children and adults. However, she sleeps 12 to 14 hours a night and two hours during the day. She often has to be woken in the morning or after her nap. She has always needed plenty of sleep but we wonder whether it is normal to sleep about 16 hours a day as a two-year old.