I dont know about that young of a baby, but as long as she is still nursing, and eating healthily, dont push the milk issue. My son was never a milk drinker. Only now he will occasionally drink a chocolate milk a few times a week (at the most.) As long as nutritional needs are met through a _variety_ of healthy foods, you're good to go.
I personally do wonder if there are so many people with milk/lactose/etc issues because we act like it is "THE" food for babies/toddlers and they get more than they need? Just my opinion, of course.
You can certainly try and see if reducing lunch solids will encourage her to drink more, but really, is one better than the other? I dont know. Just try and see what _feels_ right to you, not what everyone else says is right.