Place water, sugar, and hibiscus flowers in a saucepan and bring to a boil. Lower heat to medium-low and whisk occasionally until the sugar has dissolved.
Remove saucepan from heat and let it stand for 30 minutes so the flowers can flavor the water. Strain and discard solids.
In a high speed blender, combine peaches, lemon juice, salt, and hibiscus syrup. Puree mixture until smooth.
Strain mixture into a bowl and chill for 2 hours in refrigerator.
Pour sorbet base into ice cream maker bowl and process according to manufacturer's instructions until thick, about 20-25 minutes.
Spoon sorbet into a freezer-safe container and cover with plastic wrap. Freezer for 6 hours or overnight.
Before serving, remove sorbet from freezer for 5 minutes before scooping.
Serve sorbet with fresh berries or sliced peaches.