In a small mixing bowl, break up the tuna with a fork. Toss with celery, red onion, lemon juice, and mayonnaise as needed until the tuna is to your desired creaminess. Season with salt and pepper to taste. Stir to combine.
Assemble the wrap: Layer the wrap with lettuce, tomato, and tuna salad. Fold in the ends then roll up tight and cut in half.
Mix together the ingredients for the lemonade.
Serve: Enjoy the wrap with chips, pickle, and homemade lemonade.