Cress is from the Northern Pod of the mermaids of Canada. She had once lived near the coral reef with the red of her Pod until something had come and destroyed her home, forcing her to flee from her home and she found herself in the seas of Washington near Forks. She had been forced to go on land in order to protect herself.

While she was there, she had found herself on the La Push beach and she had been hidden so that no one could see her tail. After all, the first law that they are taught is to never show themselves to land people.

However, a certain person had known that she wasn't human, considering that he has supernatural scent. And unlike a vampire, to werewolves she doesn't smell like a wet sock.

In school she had been spotted by one of the Cullens, and they hadn't yet figured out what she was considering she is a mix of two sea species.

She had been found out by Seth when they were talking and she got wet, exposing herself and he had seen her tail, making her go back into the water and swam away.

After they had talked, Seth had taken her to meet the pack and they had welcomed her and treated her as they're own.