When my daughter was in the NICU, the nurses couldn’t stress enough how I would be her first teacher. The same thing occurred when we went through First Steps therapy for her premature development, as well as Parents as Teachers via the local school district. Now that we are homeschooling, I think the term should be applied so much more liberally; my daughter’s relatives, peers, music and taekwondo instructors, and even her pets are her teachers.
Scoff if you like; I truly believe that anyone you meet is a type of teacher, and that perhaps school teachers should be referred to something more professional in order to distinguish between them, if they prefer. I do know many who prefer the term educator, and perhaps that works better.