This question doesn't have an easy answer. There are so many variables: the skills of the referring individual, the school's support system, institutional expectations. This is a good topic for training and development.
Does you institution offer guidance?
If you have exhausted all of your possibilities or the student's problem is beyond your help, then you must move on to the next level.
When the students issues are beyond your training. If the issue is depression, suicide or other mental health issues, a professional is ideal. As the instructor, that the student trusts and approaches with the issue, I meet with the school counselor first then introduce them to the student.
When the student has a behaviour which is not consistent with the school policy.
