How many times a day should I give formula to my two-year-old daughter?

Most of my friends start to introduce their babies to regular cow's milk and soy milk after their babies are one. They use cow's milk to ensure that their babies are getting enough calcium for growth. For those who continue with formula/breast milk, they usually give their babies once in the morning and once before they sleep. Not too sure if there is any standard guideline as to how much or how often should a two-year old be getting formula. Just ensure that your daughter is getting sufficient and a balanced amount of nutrients required for her development.