Like others suggested, you can start with formula in a sippy cup, or bottle if that's what she's used to, and gradually add milk to the formula. If she is only used to drinking a bottle, then I would not switch to both sippy cup and whole milk at the same time. Unless, if she does fine with the sippy cup and prefers it, then go for it.
Here are two great articles:
http://www.askdrsears.com/html/3/T030800.asp "Feeding Toddlers: 17 Tips for Pleasing the Picky Eater" It has good ideas for introducing new, healthy foods to toddlers.
and
http://www.askdrsears.com/html/4/T040200.asp "ABC's of Teaching Nutrition to Kids" I thought this one was especially good because it teaches parents how to make learning about healthy food fun for kids. It talks about how to educate kids so that they make healthy choices on their own later on and so they know which kinds of food are healthy and why. The only thing I didn't agree with was that he suggested rewards, but everything else was pretty good advice. The article talks about referring to "grow" foods for kids.
It is not too early to start doing this. At her age, you can help by introducing a wide variety of different foods. My niece even eats avocado straight out of the peel (and a little mushed up). Avocado has a great source of the healthy fats that babies (and adults) need.
Make sure her diet is very colorful. The different colors in fruits and veggies represent different types of nutrients. And, if she doesn't like a food prepared one way, try preparing it another way. And remember, it can take up to 12 times of introducing a new food before a child will try it/get used to it. So, don't give up easily.