The story sounds completely contrived, but not wildly unrealistic. Like the kind of thing I would make up as a teenager to get out of being in trouble. It could totally be true, though.
At the same time, dorzolamide is a masking agent not a performance enhancer on its own. Also, the World Anti Doping Agency has a specific exemption for dorzolamide, so it isn’t banned. Even if she was taking it and not getting it from her dad’s pillows, it isn’t bannable. She probably took it to hide weed or a recreational drug not doping.