Do your job only

Today in my daughter swimming class, there is one teacher and 3 kids taking turn to swim. Then fourth girl comes 6 mins late. Her mom was struggling to put on her swimming googles . The teacher offered to help and spent about a min or two for that. I being the mother of a child who is already on time and waiting for her turn got a bit uncomfortable as in why the teacher offered to help.
I was that teacher in my previous job. Trying to help others and in turn irritated few people who I was accountable to.