A huge amount depends on the relationship your daughter and you (and other parents/significant adults if any) share.
She may feel in control and comfortable. She may be testing the water. She may feel peer pressure (and if so may or may not recognise it or see it as a problem). She might be stressed if its the best of a problematic situation. She might be happy to discuss, embarrassed, not believe you'll understand. She could be right even if wrong, or wrong even if right (right/wrong for her and at her age vs. absolutely and dispassionately right/wrong). It could be important to reassure or open the topic or might be important to stand back and give her space for a long time herself. In her peer group there may be ways to handle it different than those you might push upon her that would help. Consider whether she needs it or if it's that you feel the need to say it.
I say this to try and emphasise how nobody else can say "one right answer" that's right for her, for now. Its possible you can't either. Could you cope if that were so?
Doing nothing is the hardest thing. Sometimes its and is right in some cases, sometimes notwrong in others. But much more often, even if right, it's very hard to do, since we often feel we "have to do something"; yousomething". So you need to considerbear that urge in mind, in case you feel it andbut its not right for now.
(Remember the old saw about politicians' and business leaders' reactions to a sudden perceived problem - "Something must be done! This is something. So we must do it!")
KnowingThat said, and knowing nothing of either of you, I would say the crucial thing might be an awareness that many people - even while semi-liking attention - at times wish it wasn't as it was.
It also might not just be with friends and when you're around, it could be other contexts - I've seen people stuck at bus stops who didn't know comfortably and safely how to tell a stranger insistent on dialog, that they didn't want to talk to them, and that's a situation that should concern anyone as it's not ambiguous.
For that reason if nothing else, it is worth carefully considering whether to say something. But everything I've said above can shade that - it may not be right now, or for this situation, or that specific daughter, or broached a particular way or at a particular time, or might not be heard as you wish it in your relationship. It's extremely individual.
If you do think something should be said, don't rush it and think hard. If it's honestly right, maybe tell her, without specifically mentioning any specific incident, that she may find people paying her attention or being pushy and not know how to handle it or what to do if she doesn't want to tell them aggressively to go away, but also doesn't feel entirely comfortable. If so, there are things she can do and you'd be glad to help, now or whenever its useful.