Hastings MP Helena Dollimore says she is "greatly inspired" by Maria Dennis's campaigning.
Harry Dennis, 11, died as he was struck by an unsecured scaffolding board in Hooe.
Maria Dennis is calling for certain qualification requirements to be broadened to cover more HGVs.
Police are appealing for witnesses to the two-vehicle collision on the A259.
Emergency services say the road between Bexhill and Westham will be shut for the rest of Thursday.
Harry Dennis was killed when a scaffolding board came through the windscreen of his father's car.
Harry Dennis died in hospital, three days after he was seriously injured in the collision in Hooe.
