I'd suggest eating spinach and other green leafy vegetables in your diet every day, and also adding a tablespoon of sesame seeds to food or salads as that is also a very high source of calcium. You could also try drinking rice milk which is calcium enriched.

I wouldn't worry too much, DS doesn't have any dairy in his diet and i dont have much dairy in mine, i just make sure we both eat foods naturally high in calcium such as those i mentioned.