Nudes

What age do you think it's okay to send nudes, if any age? My friend (f, 15) told me she had sent some to people and when she told me I was shocked as I don't think it's right to at 15. Is this bad? Should I feel like this?

I don't really know what to say as personally I disagree with her choices but she's my friend and I respect her choices so I just told her that I don't agree but it's her body....

I kind of feel like everyone is growing up and I'm really innocent and idk what to think someone help?