This should further your acknowledgement of your error. As it states,
Quote:
A NO PARKING sign means you may stop only temporarily to load or unload merchandise or passengers.
Your mom unloaded you, waited, and then loaded you. Note the and, not the or, as a pose to the law as written above. In the fire hydrant case, they are referring to the general parking law which says that you may not park within 15 ft of a fire hydrant. This is different from a Fire Lane/No Parking zone. Those zones are designated that way not necessarily because of a close proximity fire hydrant, but because of it's close proximity to a high traffic location where they would need pre-designated area to setup. 
