Maria's parents, José and Raniya, were both new college graduates and foreigners to Europe when they met each other at a popular pub in Wales. Almost instantly, they felt a connection and it was within only two years that they were looking for new jobs, along as an apartment and carrying their only child. Within the year that Mary was born, they moved to a nice, little place in Berkshire to raise their perfectly regular daughter.
Like most infantile magic users, Mary's had her fair share of incidences suggesting to her abilities since her first couple years of life, from the usual unusually fast hair growth to minor psychokinesis and everything in between, but nothing that really aroused any suspicion in her overly regular parents. Anything that was worth calling a major incident only ever happened in Mary's primary school, or anywhere else away from home, and was only ever told to her parents via a phone-call home. Because of this, it wasn't until a special messenger showed up, when Mary turned of age, that they were introduced to what had been around them all along: the wizarding world. And even then, they were initial skeptical, but thankfully open-minded enough after several trips into this new world that their concerns over sending their only child to a boarding school that'd been advertised as tuition-free; pardon them for thinking it rather shoddy, initially.
After having been painstakingly regular all her life and then learning the origins of her inexplicable gifts (turns out there was, unsurprisingly, a wizard in the family), Mary fell in love with the new magical world she'd been introduced to. Even now, well within her fourth year, she is amazed by everything around her, always seen with her chin tilted up at all the things on her walks to and from class; though not as awfully as she had her first year, a part of her still fears there will be a morning where she wakes up, not snug in her canopy bed, but, rather, by her mother calling her to wake before she misses her bus and find that Hogwarts had been something she'd made up.
Though, this awe she harbours for the wizarding world doesn't come across when she often abuses her magical abilities and, admittedly, neglects her schoolwork.