I believe that you are confusing the word stringent with the closely related but somewhat different word strict.
Oxford Dictionaries Online says that stringent is a word used specifically for “regulations, requirements, or conditions”. As such, it is not a good fit for use on people. They prove many, many examples, including these few:
- ‘For this reason, the World Bank imposed stringent conditions on Chad and Cameroon.’
- ‘This is now rare, as there are stringent regulations to limit exposure to such a hazard.’
- ‘He also argues that more stringent requirements need to be laid down.’
- ‘The council claims Hornets have still to meet certain stringent conditions that were important to the deal.’
So the word does mean “strict, precise, and exacting”, but only for regulations and such, not for personalities. Personalities can be those other things, however. If a person is strict, then they expect rules about behavior to be followed closely, without deviation from the appointed course. More Oxford examples, this time for strict:
- ‘Most people try to put at least some distance between them and their parents, particularly if they've undergone a strict upbringing.’
- ‘Later a delegation demanded strict action from chief minister and state home minister.’
- ‘The boys had obviously gotten a pretty strict upbringing both at home and at school.’
- ‘James Sette's mother may well have had a strict and difficult upbringing, but at least she survived to have a life.’
- ‘During the Victorian lesson, Ms Roberts had the pupils reciting prayers by rote and kept the classroom atmosphere strict and formal.’
- ‘One parent is too strict with the children, the other too easy-going.’
I hope you can see now the difference in usage between these two closely related words.