Is she eating 3 meals a day? How many food snacks? How much whole milk does she get those 2-3x a day? At 12 months most babies only need about 12 to 16 ounces of milk a day (and then another 12 to 16 ozs of water diluted juice a day) if they are eating solids good, so if she is getting 3 to 4 oz of whole milk 2 to 3 times a day it stands to reason she will nurse less.
If you want to continue I would stop the whole milk and if you need to be away from her have your hubby offer her water, diluted juice or a food snack. I bet you will see her come back to the breast in no time!!!