Whether this is for you
Ziplining asks for less than people expect. You do not climb anything, you do not need any strength, and you are clipped in from the first platform to the last. What it asks for is the willingness to step off a platform, which is a decision you make nine times.
The hard limits
Two of them are not negotiable, because they belong to the equipment rather than to anyone's judgement: riders go alone from the age of 10, children from 5 ride together with a member of staff, and the maximum weight is 120 kg. The operator also advises against the course during pregnancy. None of this is checked when you book — it is checked at the harness, which is why it is written here.
If you are afraid of heights
Honestly: it depends which kind. People who dislike ladders and balconies often do fine on a zipline, because you are never balancing and never holding on — the harness does all of it. People whose fear kicks in at the sight of open space below them tend to have a bad hour. Nobody is pushed off a platform, and there is no way to leave the course halfway, so the decision is best made on the ground.
With children
From 5 they can ride tandem with a staff member, which most children treat as the best part of the holiday. From 10 they go on their own line. The tree house break in the middle is what makes it work with younger ones — an hour of concentration is a lot to ask, and the second half is a drink and a view.