Minnow is a cyborg. She was born with four stumps and requires prosthetic limbs to get around. Her quality of life largely depends on the quality of whatever parts are available at the time. She is also autistic, and not many people understand her or others like her. Viewing the world a little differently than others, she is more clever than she lets on. While still innocent in many ways, she is surprisingly cunning, able to quickly formulate plans that make the most of her current environment, using whatever is available in seemingly roundabout but ultimately effective ways. Having spent years trapped doing menial labor in a squalor where her health suffered, and stuck with beat up hand-me-down limbs that didn't work very well anymore, it's later through a series of chance encounters, some with people she'd rather not meet, that she is able to show her true talents. This leads to many opportunities she could not have seen coming.
Her origins are a relative mystery. The night she came aboard the Balena was a stormy one. Just as Andrea was preparing the ship to dive, she heard a distant screeching and looked to see two dolphins (actual dolphins, not dolphin merfolk) carrying an unconscious and severely injured Minnow to the ship. Had Andrea not waited a moment, Minnow's story would've ended that night.