Aio finding these screenshots in my girlfriends phone

Ok so I don’t really know how to go about this, me and my girlfriend have been in a relationship for over a year now and she has never given me reason not to trust her. She has given me permission to go on her phone whenever I’d like and tells me I can look at whatever. We usually share our phones on a daily and there’s no issue. Well tonight I was on her phone just looking at pictures and what not and realized I had no idea what was in her hidden folder. I know of a few pictures that were in there because she showed me when she put them in there but idk I’m just curious so I went and looked and found these screenshots from a month and a half after we started dating. Would I be overreacting if I brought it up to her and also does this seem like she cheated? I can’t see any other messages as she has the person blocked on Snapchat. For reference we started dating feb 15th and the first picture is from April 18th and the second one is from April 24th. What do I do 😭