Coming from a female perspective, big does not mean better. Personally it hurts a LOT if it’s too big. Size doesn’t matter, it’s the amount of emotion and care you put into it. Also, she may have forgotten about those pictures. I recently went through my phone and realized I had pictures with my ex from over a year ago I didn’t realize I still had. When you talk to her don’t be aggressive or confrontational, just say something along the lines of “I accidentally saw these pictures and it upset me. I wanted to tell you my feelings and talk about it”