Hi C.,
Congratulations on nursing your daughter for 12 months! That is great!! Pumping at work can be very time consuming and energy consuming and it is great that you have been able to do this wonderful thing for your daughter. I stopped pumping at work with my son when he was 15 months old.
My suggestion for getting her to like cows milk would be to mix it with breastmilk at first. Try putting in 90% breastmilk, 10% cows milk at first and then gradually work up to 50-50 and then finally to 100%. It will probably take a few months to get there - but doing it gradually will help your daughter to get used to the taste. You can also try Rice milk or Soy milk if she doesn't like the cows milk. Rice milk is very thin and sweet - kind of like breast milk. Soy milk is much thicker and not as sweet - but a very different taste to cow's milk.
For you, you will also want to gradually wean yourself off of the pump so that you don't get engorged or an infection. My suggestion would be to start pumping only 2 times at work, instead of 3. Do this for about a month, then go down to pumping only once. Do this for about a few weeks to a month and then pump, but only enough to relieve any pressure - don't fully empty your breast - after a few weeks of doing this - you can wean yourself off of the pump. All the while, you can still nurse your daughter in the AM and at night. And if you want to, you can nurse her more frequently on the weekends. Your body has a very well-established milk supply by now and will adjust to whatever amount of nursing your daughter needs. I pumped for 15 months because I wanted to be able to nurse whenever my son wanted it on weekends without having to supplement. I spoke with a lactation consultant and she said that I could wean myself from the pump during the week, but still nurse on weekends. Just to drink lots of fluids on Fridays in preparation for it and that I might feel slightly "full" on Monday's when I went back to work. Our bodies are amazing things - and they will adjust to whatever your daughter needs.
Good luck!
J.