Ladies i lost some sexting pictures that my gf sent me. How do i tell her?

My gf has this habbit of sending me picture of her Butt in her panites. Needless to say i dont stop her. She is 33 and were both adults so its not a legal issue. She takes close ups of her butt, and thats it. never any face shots or anything that is indecent. To me it was always harmless flirting, and i didint take it seriously. Until i lost my phone. Now i dont know how to tell her and i am really scared about these picture coming back to bite her in the ... butt..I think i am just being paranoid, especially because i only had 4 pictures ( out of the hundreds she would send me) and they werent in the text form ( i had saved them to the phone picture folder, and so the data from the text was no longer attached) , and the pictures are in diffent settings, i dont think they are in her bathroom( probably her work or her sisters bath room).None of them show her face, they are all elbow down. Is this somethig she should be embarresed about. i mean .. she shows the same skin when she goes to the beach in a bikini. and sometimes more, and the worse picture was one of her in a thong. They are taken from an agle so you cant even see the kitty from behind. How do i tell her and will she get mad ..... she used to be a model, and is confortable with her body .. she has even asked for me to take her to a nude beach.... so .. i dont know how she will take this....