Long ago, before the great floods, Miriam was born to a rather busy couple within the port city of Slateport. Her father, a sailor, was often out at sea, and her mother, an engineer at the local shipyard, tended to pull long nights at the yard, leaving Miriam to spend most of her childhood at her grandparents. With the ocean nearby, Miriam typically found herself building sandcastles on the beach or shooting "water guns" back and forth with her grandfather's Feebas. Sometimes her parents would catch a break from work and show up with goodies from faraway places, like Sinnoh or Kalos. Life was good, but ultimately nothing lasts forever.

When the great floods happened, Miriam was barely seven years old. She struggled to understand the dangers as her parents had, being just a child at the time. It certainly didn't help that her parents told Miriam that they were going to go on a vacation to distract their daughter, who was unaware that her grandparents stubbornly refused to leave the home they had known for generations. Before the family fled, however, her grandfather passed his Feebas onto Miriam, and told her that he would be waiting to hear all the stories and adventures the duo had when they returned.

Nevertheless, when Miriam realized what was happening, she found herself troubled and angry. The very memory of her grandparents drowning in the flood that wiped out Slateport often led to nightmares, some of which continue well into adulthood. That aside, life would have to continue on for the girl and her family, who would bounce from settlement from settlement in search of safety. Sometimes they would be in a settlement for a day or two, or they would've stayed a couple of weeks to a month or more. "Home", or at least Miriam's version of it, was now the open road, giving her a chance to experience the devastation–and beauty–of the new world firsthand.

By the time Miriam had neared her teenage years, her family would soon settle in a colony known as "The Shoal". While the settlement was hardly a place to raise a child, the Burch family settled in nicely after her father reunited with one of his sailing buddies. Once settled, life soon returned to how it was before the floods–or at least as close as it could. Her father returned to his sailing days, sailing up and down the Shiver Rill, and her mother ensured that the fleet stayed afloat with her technical knowledge as an engineer. Rather than follow her parents' footsteps, however, Miriam took an interest in the colony's diving teams, and soon was on her way to become one.

Although Miriam was a talented recruit for the divers, being already skilled in some procedures before the floods, she was often looked down upon by her colleagues for this very reason. She was a golden child as far as anyone knew or cared, and it wasn't unusual for Miriam to be picked on or left to do the work of a team by herself. Not that Miriam cared, for as long as she had Marie, she was fine with being the black sheep. In any case, time went on, and soon enough, Miriam and her colleagues were full fledged divers and placed on a team. It was here when she received Edison, a Chinchou given as a pity present due to the beliefs surrounding Feebas.

Nonetheless, the damage was already done. While Miriam was rather capable of working in a team, she regularly found herself at odds with them. Her team, having previously been tormented by them, would often try pressuring Miriam into riskier dives, ignoring that she felt rather uncomfortable with the dangers. Miriam struggled to agree with putting her life on the line for a chance to strike it rich, and despite attempts made by her to find common ground, she went on to quit the team in favor of solo diving. At least with solo diving Miriam could work at her own pace, even if that meant forgoing the next biggest thing.

Unlike most in the Shoal—or anywhere, really—Miriam has regarded her new life with a cautious approach. With the great floods throughout the world, surviving has become reality, and Miriam struggles to fathom the idea of taking necessary risks— especially as a diver. You might drown at sea, lose an arm to an angry Clamperl, or die to a dangerous poison from a Tentacruel. All in all, how can one make a living if they're either dead or horribly maimed? If rationing supplies means staying alive and in one piece, then Miriam is certainly content with the choices she has made so far.