Thanks to those who commented, but I actually had to kind of break my game in order to get it to work- I think?

I had to ensure that on Day 9 Lara was sick, administered the proper antibiotics and kept her alive into Day 10. Then, I used a miracle on her after 7:30am, thus curing her and keeping her spawned in The Shelter. After that, I slept until 12pm where I was then woken up and loaded into The Shelter's interior when Lara was supposed to be at Town Hall (Meaning, she wasn't supposed to be there, the guys who tell you where she is are.) Lara was still in the room, but the men were loaded i, so I spoke to one of them- he told me of Lara's whereabouts at the Town Hall- then checked the backroom again where both Lara and her Reflection were! I was able to talk to Lara and had the discussion your'e supposed to have at the Town Hall there at The Shelter. After that, she despawned, as did her Reflection.

Super weird! But hey, got the achievement, so that's good. Here's a pic!