Soften the frozen fruit in the microwave or by leaving it out on the counter for a little while. Blend the peaches with the water. Blend the raspberries with the coconut milk. Combine the two fruit purée mixtures and stir in the chia seeds, flax, honey, and salt. Let stand for 10 minutes to thicken.
Serve with toppings of your choice. Store leftovers in the fridge for up to three days - add water to leftovers to rehydrate (the chia seeds will soak up a lot of the moisture, making them thick).