To solve this problem you must apply the proccedure shown below:
1. Let's make the conversion from 3 pints to cups:
2. You have that 1 cup of frozen peaches weighs about 6 ounces and you obtained that 3 pints are 6 cups, therefore, let's make the conversion from 6 cups to ounces:

3. Finally you can divide 36 ounces by 12 ounces:

Therefore, the answer is: Three (3) 12 ounces bags of frozen peaches.