Breastmilk vs whole cows milk

I’m breastfeeding my 18 month old. I hear that cows milk is good for her but I’m confused- is it better than breastmilk? Do I need to be giving her cows milk if she’s still breastfeeding (we otherwise don’t have it in the house)

Help!

** edit: no I don’t want to supplement and I think breastmilk is the greatest thing ever! It’s just that pediatricians and other people are saying that cows milk is good for her particularly for the calcium and it was making me feel like I was depriving her of nutrients by only giving her breastmilk?? Why don’t we celebrate breastmilk more ugh