I think it is a little odd. I had a family once that the dad used to drive by my house in his work truck (totally noticeable) at random times during the day and evening. It was creepy. I could see driving by during daycare hours to see if we were outside playing but not in the evenings when the kids were not here.

I had another mom who would peak in the basement windows when she came to pick up her child. She only did it in the beginning until she got comfortable with me.