Put about half of your watermelon in the ninja creami pint.
Blend watermelon with an immersion blender. (see notes)
Add remaining watermelon and blend. If it passes the fill line of your container take some out.
Add the rest of the ingredients to your pint container.
Stir to combine.
Taste and adjust ingredients if needed.
Freeze on a level surface for 12-24 hours.
Place pint container in the outer bowl of the ninja creami machine. (Make sure the pint lid is removed)
Place outer bowl lid with blade attached on the outer bowl and click it into place.
Attach bowl to creami machine.
Process the watermelon sorbet either on the 'lite ice cream' or 'sorbet' setting.
Check the creamy. If it is crumbly process it again with the 're-spin' setting, until it reaches your desired consistency.
If you want to use a mix in add those in now and process with the 'mix-in' setting.
Enjoy as is or add some toppings.