Other dairy products such as cheese and yogurt are equally good sources of calcium. Choose the low fat options - they contain no less calcium than the high fat types. Research work has found that bone strength is increased until the age of 35 years. After that, calcium absorption is decreased. So get your calcium sources early and encourage the young to choose calcium rich foods.
Calcium is also present in other well-known foods.
If you are a vegan and don't drink milk, there are other sources of calcium equal to 1 cup of milk that can be chosen. Unfortunately, I find it hard to get children to consume large quantities of broccoli, almonds and tofu at the best of times. Be very careful if you decide to have your children adopt this lifestyle. I didn't manage to drink any milk or eat any yogurt or cheese today, I'd better take a calcium supplement. Missing one meal or missing one food on a day is not cause for concern.