As pp have said it is common to begin uni at 17 in Scotland, and most will cope fine.
Regardless of age, there are three main areas where uni students need to cope with to be successful, and generally they'll be fine if at least two out of the three are on track at any point in time.
The first is academic preparedness - is the course suitable for them? Are they capable and interested? Did they choose the uni for them, not because parents liked it or their girlfriend lives nearby?
Do they realise that they will need to independently study? Keep up with materials and seek help if they can't understand or keep up?
The second is social - do they have an interest already so they can join the choir/basketball team/chess club? If they don't have an interest do they recognise that joining clubs and societies is the best way to make friends and build a network? And actually how important that it is to meet people, as well as maintaining contact with friends and family from home.
And lastly, can they look after themselves? Can they prepare some meals, use the washing machine, clean the kitchen? Do they understand the need to clean up after themselves in shared flats, to live considerately with others? Can they budget and live within their means?
And if anything goes wrong, do they know they can come to you for support and help to navigate through any difficult situation?