Claire Donovan is the younger sister of Joshua and the older sister of Claudia Donovan. While she isn't quite as smart as her siblings, she could be described as a musical prodigy.
At the age of 15, Claire unknowingly bought an artifact at a garage sale. The seemingly innocent music box caused a lot of damage. It tied itself to Claire's emotions, enhancing her negative feelings. She had several telekinetic outbursts, and ended up destroying the artifact and killing her parents by accident. She'd become a danger to herself and others, so the Regents of Warehouse 13 put her into an artifact-induced coma for fifteen years.
When Claire was 30, her little sister found out about her condition and woke her up. After a few failed attempts to save her, the energy of the artifact was transported to an alternate dimension.