Combine jam, sugar and lemon juice in a small measuring cup. Whisk to combine ingredients. Set aside.
Combine fruit in a large bowl. Pour dressing over fruit. Stir until fruit is completely coated.
Serve immediately or place in the refrigerator for 1 hour, or up to overnight, to allow the flavors to meld.
Notes
The longer the fruit sits, the juicier the salad will be. If you want the fruit to remain dry and crisp, I recommend serving the berry salad immediately after making it. If you prefer your fruit soft and macerated, like a fruit salsa, allow it to sit in the refrigerator for a few hours. I enjoy it both ways.