Why was your new girlfriend snooping in your closet? That should be a big red flag right there, imo.

I agree those are your memories to cherish; she shouldn't have asked you to dispose of the pictures, especially after you had the decency to pack them out of sight. That she did suggests she may be somewhat immature and insecure.

My husband has carried a picture of his first wife with his (now deceased) first daughter in his wallet for our entire 19-year marriage. They're not a threat to our relationship, and I would never suggest he get rid of them. Just another perspective.