In reply to BarrySW19:
When you're getting lo larger weight differences, the only way go give a hard catch, is to either up your weight (heavy rucksack or sandbag) or use a ground anchor. When climbing with my lightest climbing partner (40kg difference), if I'm concerned about a bad fall, or she's concerned about being kicked in the face, we usually go with the rucksack full of rocks approach.