Lovely story!
There's not always logic in who people confide in. I feel like most of my students trust me enough to come to me if somethings wrong but I have this one student who I only thought in one subject last year for one hour a week who seeks me out like three times a week. I don't have that student in any classes this year. Sometimes it just clicks for someone.
Oh, it is a strong connection then if that student can come to you so many times a week. It doesn't matter you don't teach that student this year, sometimes the former teachers just stay in the same trust connection. :)