Lemon Pudding Fruit Salad

1 large (20 oz.) can pineapple chunks, drained with juice reserved
1 (15 oz.) can mandarin oranges, drained with juice reserved
1 (3 oz.) package lemon Jell-O
1 (3 oz.) package lemon pudding (not instant)
1 tub cool whip
2 c. fresh strawberries, sliced
2 c. bananas, sliced
1 c. miniature marshmallows

In a large saucepan, combine reserved fruit juices and enough water to make 3 cups of liquid. Bring liquid to a boil. Mix in Jell-O and pudding mix. Cook and stir until thickened. Let this cool. Stir in cool whip, fruit and marshmallows. Refrigerate at least 1 hour. If not serving that day, wait to add fresh fruit until right before you serve.