My son is allergic to cow's milk and cow's milk products like
cheeses, butter, regular ice cream. momof9's suggestions are
awesome (thanks!). We also like Silk. But my son now hates
soy milk as my DH "hates" soy. I'd be cautious with the Almond
milk unless you are certain your child does not have a tree nut
allergy. Mine does. But not a peanut allergy. Rice Milk is another option. You could also check on goat milk, which my son is not allergic to. Nor is he allergic to sheep's milk and cheese. We are fortunate there is a Whole Foods store within driving distance so we
can get Meyenberg goat milk as well as other products he can have.
Also check the orange juices for those that have calcium. We're wary
of too much of other juices as we also watch sugar intake. Good luck

We have two children who are allergic to dairy in our home. This is a government web site that has all you need to know about calcium including required intake and sources of calcium etc. http://ods.od.nih.gov/factsheets/calcium.asp
As for the soy wellllll soy itself has very little or no calcium. And some of it is disgusting! However many soy products have added calcium but so do a lot of juices, cereals etc. So if your child hates soy don't get too upset. However you may want to try different brands. My children like tofutti brand items. They have sourcream, ice cream, yogurt, ice cream sandwhiches "cuties", and lots of other dairy substitutes they even have portable drink boxes and they are great tasting. We like Silk brand milk the children prefer the chocolate, strawberry and very vanilla to the plain. I use the plain to make biscuits, gravy etc. I switched our whole family to no milk over about 5 years time even my DH has switched though, he still does not know it. I started by adding a tablespoon of silk very vanilla to each gallon of milk I bought. Then 2 Tablespoons etc. Now I just wash and resuse the old milk containers and we are straight up silk. LOL. My DH ordered a glass of milk in a restaurant and thought it was bad because he has become accustomed to the soy now. By the way my DH has a brain injury and any changes in routine upset him thus the need for the stealth when changing to soy. My brother "hates" all soy and when he came to our house for Thanksgiving he ate everything we had fixed and was saying how wonderful it was to have "real homemade cheesecake" again. My allergic daughter took a slice and he said I thought you couldn't eat or even touch cheese. She just smiled and said that it was soy. The look on his face was priceless especially when he learned that nothing else he ate that day had dairy either. We have been at this for a lot of years and so we have learned by sheer trial, failure & sheer desperation to make almost any creamy, chocolatey, milky dish without milk.