I think you are already realistically aware of your responsibility in this situation is, but your wife can make some actions on her behalf as well.

She doesn't need journals or emails about sex with her ex. She is with you and she doesn't need to revisit experiences with someone else. The mementos are also a little weird, you can ask her to stash those away. And lastly, the comments such as "I went here with my ex" are unnecessary. She could have said "I went here before." It's kind of a simple concept that may make no sense to her but I think for everyone it's just polite to erase the unnecessary details.