
In a blender, puree the watermelon until all chunks are gone.
Strain the mixture if to remove any seeds.
Add the sweetener and lime juice. Blend again until everything is pureed well.
Pour mixture equally into 10 popsicle molds. Attach covers and sticks. Note: don't overfill the popsicle molds, as the mixture will expand as it freezes.
Freeze popsicles upright until firm, at least 3 hours or up to 2 weeks.
Hold each mold up to the rim under warm running water just until paletas are released from sides of molds, 5 to 15 seconds. Remove covers and pull out popsicles.
Eat immediately or store in freezer.