I have leveled up the raccoons multiple times and the wife’s shop won’t gain any new items. It’s a single player world and the version number is v1.6.9 build 36
Same thing is happening for us in multiplayer. We're on xbox. She is only selling the seeds for carrots, squash, broccoli and powder melons. Shop has been leveled all the way to the point where we were rewarded with fairy dust, but its still only the same 4 seeds.