Sounds like you kept your cool admirably. Well done.

Would I have done things differently? Yes... but I have a lot of experience with children. I'm used to holding boundaries, and my adrenaline wouldn't have spiked. I would have said quite a lot more to the preteens, firmly, but not raising my voice much.

As an example, I was in a large jacuzzi in a hotel when a group of teenage boys also got in. One of them talked very disparagingly and crudley about some girls in the swimming pool and all the boys laughed, and two joined in with the crudeness.

I told them how disappointed i was that they said such things, particularly in front of the myself and the other two women in the pool. That their mothers and grandmothers would be mortified to hear them. I met each of their eyes and most of them blushed or looked very abashed. Two tried to brazen it out, so I spoke to them directly. And after a very short time they both apologised.

I think, generally, our society is scared of standing up and speaking out, and yes, there is a small danger in doing so, but that danger is only present becase not enough people do it.

I would have used what happened as a teaching opportunity for the preteens, and my own childen. I would have definitely discussed it again with my own children afterwards at home, going through different scenarios like, what if they were on their own etc

It's worth looking at non violent communication for yourself, and modeling it to your children . Self confidence and articulacy are the biggest self protections. Your children live in a society that allows bullying and rape culture to be prevelant. So you need to bring up children who can defend themselves in every way.

There were no consequences for those preteens, so that encourages their behaviour. Every single adult in that space allowed that to happen. And you felt unable to do it on your own. Most people would do what you did.

If you want to be more able to deal with these things and teach your children not to be victims, then you need to learn those skills.. self defence, non-violent communication, de-escalation techniques- and read up on how children's, pre teen' s and teen's brains work.

The first few times, when your wound up and full of adrenaline, you won't do brilliantly, but it's like first aid, the more you do it, the easier it gets.

The most important thing as a parent, is to be gentle with yourself. Acknowledge all the good things you did in the situation, and decide if you want to do the same, or differently next time. We all do the best we can. All the time.