N.B.
My daughter was/is lactose sensitive, but mostly has outgrown it enough to be able to eat enough "normal" things without too much adverse issues. She is 16 now, so decides what she can and will eat and deals with the side effects. She loves cheese and things like stuffed pasta meals, but is not big on milk, so for her it is a balance.
She never had milk on anything resembling a regular basis until she was about 6 or 7 (like on cereal, etc) and the products available now were not so plentiful, price affordable or tasteful as they are now (my opinion)...so we did supplements and diet changes to get calcium and vitamin D (as per the nutritionist at the Peds suggestions)...
Good luck!