The prefix "mrs_cristin_caitlin" suggests the photographer or studio.
Search your local storage specifically for "RU012317" to find all related photos from that set. mrs_cristin_caitlin_RU012317_lrg_176
Search your inbox for "Cristin Caitlin" or the project code to find the original delivery link or download instructions from the photographer. mrs_cristin_caitlin_RU012317_lrg_176
Since this is the "lrg" version, it is likely the best choice for physical prints (up to 8x10 or larger depending on actual pixel count). mrs_cristin_caitlin_RU012317_lrg_176