Add all ingredients to a high-speed blender, blend on high for about 1 minute, stopping once to scrape down sides. I recommend taste testing at this step to make sure that your mixture is sweet enough for you. If needed, add a teaspoon of additional sweetener like table sugar, honey, or syrup.
Pour into the Ninja Creami pint container, cover and freeze for 24 hours on a level surface.
Run lite ice cream mode x1. Scrape down the sides of the pint container with a spoon.
Run respin mode x2, check the consistency. If the mixture is still crumbly at this point add a very small splash of milk and spin a final time.
Notes
Make sure your peaches are ripe! They should have a slight give when pressed and smell sweet. Peaches that aren't ripe enough are much tarter and won't give a sweet enough ice cream.Before freezing, test taste your peach mixture to make sure it's sweet enough. If it needs it, add 1 tsp at a time of honey or maple syrup.