Cut the pears into slices thick enough for shaping. Use a small star-shaped cutter to create pear stars.
Squeeze lemon juice over the pear stars to keep them fresh and bright.
Slice the watermelon and cut out star shapes using the same cutter.
Remove strawberry stems and cut each berry into quarters.
In a bowl, mix the quartered strawberries with blueberries until evenly combined.
Add the pear and watermelon stars to the mixture, folding them in carefully to maintain their shape.
Serve right away or chill briefly before serving.
