Since I've done this train ride, I'm happy to share with you details of the trip.
As for Zinnia, I think my biggest issue is the fact that she IS a minor doing all this. You even bring this up when Zinnia talks about trying to find a place to rent. There are times when I do ignore the game's logic because it's at least plausible, but the fact that she's a minor and she effectively runs away from home is a big no-no for me. Honestly, I would prefer if she weren't a high school student altogether. Instead, have it that she's at least 18 years old, is done high school but she didn't apply immediately for college because she wanted to work and save the money up (which she claimed was for college but in reality it was to save up for the very thing she's doing now in the game).