Had the exact same problem last summer trying to remember this food blogger's spots in Portland! Super annoying when accounts go private right when you need them. I ended up using https://viewverio.com/ after my travel group suggested it and managed to screenshot the restaurant locations I needed.
Worked out perfectly because we recreated this whole food tour and hit like 6 of the places she recommended. My friends still talk about that donut shop we found through her old posts lol. Memory is definitely not reliable for trip planning so having access saved us a ton of guesswork. Good luck with your cousins trip!