Should I have stayed out of this?

My soon to be 13 year old granddaughter came to me today, and told me one her brothers friends had come over and, when her brother introduced him to her, had a made a comment that she overheard. Something about “Wow, your sis is hot”. I just told her not to worry about it, unless he tries to her frisky with her. At this point it’s just boys being boys. My wife told me to stay out of it but Sandi had approached me about it, so I gave her my opinion. I don’t feel I was butting into anything?