What are the rules for non-competitors walking with a card at a sanctioned event?

I’m visiting a friend this weekend while playing in a C-tier on Saturday. Her mom is interested in learning more about the sport and wants to tag along on the course. She won’t be throwing or anything, just watching and keeping company. Is there a rule against that? If necessary, I could say she’s my caddy but still carry my bag, but I was hoping I wouldn’t have to use that excuse.