Marinette is the only child of Aquaman and Wonder Woman, and was raised by them during her childhood. Anyways, there was an accident, and Aquaman and Wonder Woman made it out together, but couldn't find Marinette, eventually, they gave up, and thought she'd died in said accident.

However, Marinette didn't die in the accident. She escaped on her own, believing her mother an father were dead, and that she'd never see them again. Marinette went to Paris, and was adopted by a lovely Parisian couple, Tom and Sabine Dupain-Cheng.

Shortly after she was adopted, Marinette was forced to become Ladybug. For the good of Paris. A year latter, Marinette had to take away Chat's Miraculous, The next year, Marinette made a mistake, she feel asleep touching the Miracle box.

Now, for those of you who don't know falling asleep while touching the Miracle box causes the Miraculous to merge with your skin an become tattoo's on your skin where you would wear it. (a bracelet would leave a tattoo on the wrist, ect.)

Shortly after Mari merged with the Miraculous, she beat Hawkmoth and Maura, fixed their Miraculous, and then merged with them too.

Ladybug walks into the meeting rom, slightly scared of what she'll find, when she spots two people she recognizes. Suddenly she's running across the room and hugging Aquaman and Wonder Woman.

"Mom! Dad! I thought you died in the accident!!!" then "WHAT? MOM? DAD? WHAT ACIDENT? WHAT?!!!" Ladybug turned, and laughed and their shell-shocked expressions.

"Hi, Let me introduce myself. I'm Marinette, their daughter. A few years back, we were in an accident, and I thought they died." the Wonder Woman spoke to her daughter. "Mari, dear, you haven't aged a day." Marinette laughed.

"Of course not!" Superman shook his head, and said, "Wait, so how old ARE you guys?" the three of them looked at each other, and then Aquaman said,

"Well, I'm 2287 years old, Diana is 2187 years old, and Marinette is 1087 years old. but compared to the average human, I'd be about 27, Diana would be 24, and Mari would be 16."

Marinette was enrolled in G.A. and she and Damian fell in love, yada-yada-ya and with Atlantic, and Amazonian permission, they started dating, and all that.