Niamh,
making parachutes to slow down falling objects is a good way to engage the children and to help them express their understanding of forces.
The connection between weight and falling is rather more tricky, and has been not well understood over the years until the 1600s when Galileo explored this with actual experiments. He used ramps and measured the time it took different balls to roll down a ramp. In this case the ball rolled slowly enough that he could measure the time it took.
See this Nova show that outlines the thinking of Aristotle and Galileo:
https://www.pbslearningmedia.org/resource/nvmm-math-fallingbodies/galileos-falling-bodies/
and includes the hammer and feather experiment from the Moon.