technically she's the pedophile hereTypical Japanese shyness trope. She's over 900 years old, man. It's totes legal.
Series is hardly consistent on what can or cannot be done but it's plausible that the magic isn't limited by weight but by size. The smaller rocks would therefore be easier to hold in place.I don't understand how that magic works. She can't lift the car but she can make rock float that support the weight of the car?