Jake did exactly the same thing refusing milk from about 11 months??! He was on formula but just decided to go on a bottle strike one day and that was that. He'd drink weak milos and now he won't even drink them.
He's lactose-intolerant so there isn't a huge amount of chioce out there dairy-wise that fits our budget but if you're worried about calcium intake (the only reason parents generally worry about adequate dairy in their kids diets) there are heaps of other calcium-rich foods out there to feed her. Broccoli for starters, baked beans, fish and nuts though you'd probably be avoiding them for now, cabbage, oranges, rolled oats, spinach, peas, dried figs, fresh carrot & vege juice, nori seaweed, etc. I'd juice up oranges, carrots, spinach and apples for Jake and he'd scull that back getting lots of essential nutrients!
HTH