Place the raspberries and sugar in a small pan with 4 tablespoons of the measured water and bring to the boil, stirring well until the sugar dissolves. Add the remaining measured water.
Put the raspberry liquid through a sieve, pressing down well with a metal spoon to make as much of the pulp go through as possible, only discarding the seeds.
Pour the mixture into 8 lolly moulds, filling just the base of each. (Try using 8 rinsed yogurt pots placed in a roasting tin. Cover with foil and push lolly sticks through the foil into the centre of each pot. The foil will help secure the stick in the centre.) Freeze for 1–2 hours until firm.
Meanwhile, put the peaches and juice into a food processor and whiz until smooth. Once the raspberry base is firm, pour the peach liquid over the top of the raspberry mixture and freeze for a further 1–2 hours or overnight until firm.