Simone
I think we're going way off track here. Flyscreens should NEVER be seen as either a child safety restraint nor indeed an anti-burglary device. Most of them have very flimsy frames, and are attached by little plastic lugs which are often further weakened by exposure to UV radiation. The screens themselves are usually of fibreglass material and are not very strong, they can be pushed out from the frames easily as they're only held in by plastic beading. They are not generally designed to take the weight of a child falling against them. I believe the only way to stop children falling from windows is to restrict their opening or put bars on them, in the latter case it could mean compromising adult safety in the event of a fire in the building for example.
DaveB