Hey there 
the other day, unintentionally, I managed to get two readings from Katrina, despite being allowed to only get one per player file.
What I did was I got a reading from Katrina, and while she was in the middle of telling my fortune, I closed my 3DS (because I was running late for work). At around 12-1 AM I opened my 3DS to continue playing and I let her finish my reading. After she was done I talked to her again and she offered another reading, I suppose because it's technically a new day. I was surprised by this, and happy because I'm now two steps closer to the Fortune Teller Shop.
Maybe other people will use this helpful trick to speed up unlocking her shop. So I figured to make it easier, get a reading from Katrina before she closes at 7 PM. Close your 3DS in the middle of her reading and open your game back up 5 hours later at 12 AM, let her finish, and ask for another.
the other day, unintentionally, I managed to get two readings from Katrina, despite being allowed to only get one per player file.
What I did was I got a reading from Katrina, and while she was in the middle of telling my fortune, I closed my 3DS (because I was running late for work). At around 12-1 AM I opened my 3DS to continue playing and I let her finish my reading. After she was done I talked to her again and she offered another reading, I suppose because it's technically a new day. I was surprised by this, and happy because I'm now two steps closer to the Fortune Teller Shop.
Maybe other people will use this helpful trick to speed up unlocking her shop. So I figured to make it easier, get a reading from Katrina before she closes at 7 PM. Close your 3DS in the middle of her reading and open your game back up 5 hours later at 12 AM, let her finish, and ask for another.