Mary Joselyn Clarke was the second born of a grand total of four little tykes brought to the world by Maxwell, a Muggle, and Janelle Clarke, a magical wildlife keeper. She followed her oldest sister with roughly a two year difference, and was subsequently followed herself by fraternal twins Justice and Vivian just a few years later. Unfortunately, the family's happiness wasn't meant to fully flourish - unfortunately, Janelle perished shortly after giving birth to the twins after a prolonged coma, her body unable to withstand the strain it was forced to endure. Maxwell, a graveyard keeper, was forced to care for and nurture his family on a low salary ever since, as neither his parents nor Janelle's ever offered to help with the children
Maxwell's efforts seemed to pay off for a time - the children never lacked a thing despite the very tight budget, and fortunately they were all too young to remember the misfortune that had befallen them, so they were able to transition into their new lives without much trouble. Due to a lack of knowledge of the wizarding world in general, he enrolled his children in Muggle schools through Elementary education. It was here that Mary first got a taste of the ostracization that haunted her for the remainder of her Muggle academic career: it turns out being the child of the graveyard keeper automatically granted her the label of 'spooky', 'creepy', 'lunatic', among other things. The fact she was shy and soft-spoken didn't help her case, and thus she remained a very lonely child throughout that entire painful process.
A second turn of the worse expected the Clarke family around the corner: the less than ideal school ultimately cost them something very dear to them, in the form of Vivian's presence. The girl disappeared from school premises one day, never to be found. This affected the whole family, in particular Maxwell and Justice. Maxwell became overprotective of his children ever since and very present in their lives; Justice didn't seem to take so well to losing his twin, and while he remained on friendly terms with Mary, it hasn't been the same since despite the years going by.
Enraged with the event, Maxwell pulled his children from the school. It was perhaps a happy coincidence that his oldest child, Aspen, had just entered Tallygarunga to pursue an education in magic - she informed him of the existence of the Whitlam Bilby ward. Without thinking twice, he enrolled the two remaining kids in it. Mary finally got to experience the magical world, even if it was through loss - and with the exposure, she was finally able to start to read and understand the various books and notes their mother left behind before passing away, most of which pertaining to magical creatures and local flora, as well as survivalist skills. She became very attached to this treasure trove of information, as it was her way of being connected to the mother she never met. Seeking to do the same with her lost sister, MJ also took the pawn shop guitar their father had gotten her for the last birthday they enjoyed together. She's been playing it since by herself, and has become very proficient in it.
While nobody seemed to ostracize her that heavily in her years in Tallygarunga - the very campus had ghosts after all, it wasn't like she was out of place - it seemed that both the social exclusion and the disappearance of her sister had left a lasting mark. MJ was the quiet sort and never had any friends, and her reputation as a weird kid seemed to follow her even if she did nothing to gather attention on herself. She'd really like a friend or two, but she has no idea where to begin...