Yea, I was wondering myself how frequently the store restocks. I've been playing it since the day after it was released and I have only seen the supplies to fix the hose in the store one time for one family. The very first family I started are getting old and their kids are grown and gone and I still haven't seen the necessary supplies in the store yet. They keep asking me to help them do some of the necessary repairs (yep, not asking for upgrades, they have quite a few already, actually asking for help with the repairs) and I can't help much. The store won't give me the supplies to fix the hose or the supplies to fix the floors either one. All I've managed to fix is the birdbath and I do have something to fix the walls but that won't work until I can fix the hose.
Frustrating!