9 & 11 year olds wearing thongs? Thoughts?

Anonymous
I am with my family & another family (their) friends on vacation together. They decided to go off walking around the city. I was tired after spending the day at the beach, and wanted to instead stay in the air conditioned room - as to help out, I told them I would take the clothes out of the dryer & fold them.

I folded my family’s (just me and two parents) stuff, but then I got to the other family. The other family consists of a mom, a girl (16), a girl (9), and a boy (11).

I wasn’t surprised to see the thong bikinis belonging to the mother & older daughter that they wore at the beach that day. 16 years old seems young for such a bikini, but I liked it being a 17 year old dude who is kinda crushing on her. I also wasn’t phased to see larger thong underwear belonging to what seems to be the mother & the older daughter.

But, I was shocked to pull out & fold 3 pairs of really small female thong underwear, and 2 pairs of small male thong underwear. Belonging to a 9 & 11 year old child.

What is your opinion about this? Is this insane or is it something acceptable?
Updates
+1 y
I’m glad people are agreeing with me and that I’m not insane. I’m thinking of going shopping with the kids and buying them proper underwear, but at the same time I don’t know if I should mess with their business. I just feel terrible for the kids, I don’t think they had a say.
9 & 11 year olds wearing thongs? Thoughts?
24 Opinion