Magda's parents were among those Sorreters who followed Drag in joining the Protestant Movement during the Coming of the Order. When the Protestant Sorreters all vanished during the Battle of Triscot in 903, her parents took Magda with them. Nothing is known of where any of them went, or of Magda's childhood. However, she has been a spirit-talker from an early age, and is one of the few modern Sorreters to hold spirituality as an integral part of the practice of magic.
In 913, Cameron Piper went back to the hidden community of ex-Sorreters, after several years as a spy in mainstream society. At that time, he was granted master-adept status, and took on Magda (who was 16 at the time) as his first apprentice. While this has led to her becoming a Sorreter, and while she is herself a Protestant, she doesn't apply the term "ex-Sorreter" to herself, as she had been too young to be a Sorreter while actually living in Sorret.
It should also be noted that she is one of first members of her hidden community (excepting those who left to become spies) to take on a surname, in spite of not technically being subject to the law which introduced the concept to human society in 904. While her parents don't go by a surname themselves, they were apparently involved in her choice. It's unclear at what age, exactly, she chose this name for herself, though it was sometime between becoming a spirit-talker (around age 10) and becoming a Sorreter. She admits that while her choice is meant to convey that she is involved in mysticism, she understands that the correct word for her status would be "mystic." She says she just prefers the sound of "Mysticist," as it sounds more... mystical, to her.