M.
If your daughter isn't taking to the whole cow's milk, it may well be that she doesn't tolerate it well. Children who are sensitive to a certain food (and cow's milk is one of the most common irritants/allergies for kids to have) tend to naturally avoid it OR then tend to be almost addicted to it (you know those kids who basically don't eat anything other than milk, cheese, yogurt, ice cream, etc.? yeah - not a good sign!).
If it were me/my daughter, I would absolutely honor her natural preference and just back off of trying to give her cow's milk for another 3-6 months. Would you be willing to continue to breastfeed her for another 3-6 months? In the grand scheme of things, that's really just a speck of time (think of when she's 18 years old - 3 more months is a tiny drop in the bucket), and while I understand having a wide range of different feelings during the nursing relationship, there are lots of things I do as a parent that I'd rather not do but I continue because I know it's temporary and the healthiest thing. Additionally, there are some compelling health benefits in it for you as well (reduction in rates of breast cancer, endometrial cancer, uterine cancer, diabetes)! Biologically and medically speaking, there is really no need to wean from the breast at this age (don't know if you're getting pressure from family, friends, or doctors to wean??), since your breastmilk is the most appropriate food for her (human milk for your human baby) as opposed to cow's breastmilk (which is really intended for optimal development of a baby calf, not a baby human!). If it's the calcium you're worried about, please rest assured that there are many other ways to ensure your daughter gets enough calcium - leafy greens are very high in bioavailable calcium, as are unhulled sesame seeds, beans, etc.
Regardless of whether you continue to wean or not, I absolutely want to celebrate you breastfeeding for an entire year -- CONGRATULATIONS! I'm doing a little dance and cheering for you for doing something that *so few* moms and babies get to share. I really wish more moms would do *even HALF* of the breastfeeding you've done! So WAY TO GO! :)