Sharkboy And LavaGirl And SharkGirl?!

Chapter 1

MAX: "Sharkboy was not always half shark, half boy. Sharkgirl was not always half shark, half girl. They were marine biologists.  Or at least in training. Their father studied great white sharks and called his kids Sharkboy and Sharkgirl because of how much they loved to care for the sharks. They made them sushi and had given them all names. Goodmilk, Peggy, Eggbat, and Crackett. But one day an incredible, mysterious storm appeared. It swept away the entire laboratory. Thanks to their life rafts, Sharkboy, Sharkgirl, and their father survived. But they survived on different sides of the wreckage, Sharkboy and Sharkgirl on one side, their father on another. Each floating off in a different direction. Sharkboy and Sharkgirl were completely alone. Almost completely alone. But one of the sharks recognized them. They took them both to their cave home, where they'd be safe and dry. Their new family were sharks. Hundreds of sharks. The sharks raised them as 2 of their own, training them in the ways of the shark. Eventually they grew gills, and sharp talons for claws. Their teeth sharpened themselves to a point. They grew fins, all sorts of fins. But that was years ago. I first met sharkboy while fishing on the dock this summer. He seemed lost. So I snuck him home, when my parents were too busy to notice. I kept him fed and in water. He had been traveling the universe in search of his father and sister. He said his sister and him were separated a year after living with the sharks. He told me of his latest adventures on a planet so cool it makes you drool. He said I too could go to Planet Drool someday. Then one night I was visited by a glowing light. An amazing girl with purple flames for hair and skin of molten lava rock appeared. I called her...Lavagirl. She smiled at me, for that seemed to be her name. She told me she needed Sharkboy to return to Planet Drool with her, for a great crisis was developing. She asked if I could go with them. I told her, "I have school tomorrow." She gave me a sad look and flamed away, taking Sharkboy with her. I haven't seen Sharkboy or Lavagirl since then. And that's what I did this summer."
Everyone around me started laughing except Marissa. Her and I were the only ones not laughing. Marissa liked Max but the real reason why I didn't laugh was because I knew his story to be true. I am Sharkgirl but I go by Alexa in this world.