Hello there! I have a question: you need to have your fortune told by Katrina 20 times, right? My doubt is: does it count when you go to someone else's town at her shop on main street? Or only the fortune told inside the tent counts?

I tried going to my extra town to get my fortunes read in a tent.  It did not work after 20 fortunes.

To get faster in your own town send your extra players living in your town.

You can get the shop unlocked in one day by making a new players over and over.
In one of my towns I had 12 fortunes left so I put 12 1K bell bags by the tent.
Made a new player, got the house built and got it saved.  I than went up to the event plaza to get a 1K bag.
Got the fortune told and dropped the 500 bells at the train station to keep track.
Erased the new player and than made a new player.  Once I had 12 fortunes done I sent the mayor into the tent to get her fortune done.  Got the request when I left.

It does get boring making a new player over and over.  It helps to place the house in the same spot over and over so there is one dirt spot.   The snow should cover the dirt spot before it melts in  late February.