The fastest way to unlock Katrina's Shop without waiting is to get a fortune from her by your human players in your town. Then erase the last player and make a new character. Rinse and Repeat until Katrina says she will open a shop
It took about 4 hours but it is better than waiting months
only do it if you have extra space for human players however
Member of SIG. We makes tons of Bells in New Leaf!
PT me to find out more!