Cats have survived unhurt from falling from a great height than you are talking about.
Added to that a cat who jumps and does it more than once has somehow been able to judge the distance and landed safely.
I know this is not terribly reassuring, as she may misjudge her distance at some time or other and come to harm.
The fact that she chose a lower part of the roof to jump from today, shows that she herself felt the height was a bit scary.
All you can and should do, is to make sure there are no unseen obstacles where she lands that could harm her, stones, gardening tools etc. hidden in grass or bushes.
My year-old Tigger scares me by crossing a busy road to play with the cat who lives on the opposite side and steal his left-overs, even although Tigger gets enough food at home. Nothing I do will stop him, and not even his sister thumping him when she catches him coming in from the road, which she doesn't dare cross, deters him.
We have a basic choice: either we force the cats to live an unnatural life indoors, or we reconcile ourselves to the horrible thought that they might be run over, hurt themselves seriously jumping or falling from a roof or a tree or be caught and savaged by a dog. Happily, they may instead live to a ripe old and healthy age.