My mom was a bit older than the average mom of the time when she had me -- I have a brother who is ten years older than me, you see. She's 62, which isn't quite of the age where a lot of women would think seeing their daughters in work boots meant they were never going to have grandchildren, but my mom is particularly traditional and highly concerned with the way one presents oneself.
Still, I think if this happened IRL, mom wouldn't really throw a fit about me going to a construction job in work boots. I think in the dream it was more an issue where she objected to my taking the job in the first place, but it came out in the form of arguing about this side issue.
I mean, I wore boys' jeans and doc martens and thermal tees under flannel shirts to class every day when I was in high school and college, and while she wasn't a fan, she never made me late to school so we could argue about it.
Don't judge. It was the style at the time.