I find tits like her to be extremely sexy. But get rid of the pigtails. It's not about her being young, it's about her being a grown woman with a flat chest, and that is sexy!
I get so hard seeing flat chested girls / women. My first wife had beautiful full areolas and was completely flat chested but her nipples were so very sensitive that I could suck them just briefly while putting my finger on her clit applying pressure without moving my finger and she would have a strong orgasm. I DO MISS THOSE NIPPLES