Baby drinking whole milk

My daughter just turned 1 and her pediatrician said he only wants her to have 12-18 ounces of milk a day (whole milk and breastmilk combined) and I guess I’m just having a hard time trying to make sure she’s only getting that little. I had such a hard time getting her to drink whole milk at first but now she’s drinking about 5-6 ounces a day, is that enough whole milk, also how do I make sure she isn’t getting too much breastmilk? I don’t pump or anything so she just kind of gets what she gets when she breastfeeds. I’m trying to slowly wean her off the breast to make sure she isn’t getting too much but also I’m not sure if I’m ready to stop breastfeeding. Any advice is appreciated, thanks in advance!