<human>: I am friends with my younger sister on Instagram. I recently noticed that she has started posting suggestive pictures of herself. For example, bathroom pics where she pushes up her cleavage, pics where she's wearing just a shirt and underwear while making a 'sexy' pose, etc.

Because she is so young, this doesn't feel like appropriate content for her to post. If she were older I'd say whatever, but because she's just in high school it feels really creepy. I want to approach her about the pictures but I don't want to do it in a way that will make her want to block me on social media. I also know that at that age, teen girls are already going through enough problems with creepy older men treating them as sex objects, and schools villifying them just for wearing spaghetti straps, so I don't want her to feel gross about becoming a woman. Basically I don't want to 'slut shame' her.

I am also wary of going to my parents with the information because they will most certainly over react, potentially causing her to just hide her social media activity from everyone.

How do I breach the topic with her and what should I say to make her understand why the pictures aren't acceptable?

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<bot>: Underage sister posting inappropriate 'sexy' pics and I'm not sure how to show her that's not appropriate.