Ah, OK, my (Chinese) wife is like that, she won't leave anything behind, I don't mind leaving it behind, but I can understand trying to avoid waste since many places will throw away bread which was offered to other customer. And often the bread taste actually good, so it makes sense to take it.
Ah, so it's just that the OP wrote something that was prone to be misparsed.
I read "breadbasket home" as a compound noun and guessed it was some kind of food bank or something, but "home" was really an adverb modifying took. So what was meant was something like "My grandma ... always took [home] the bread from a [restaurant] breadbasket..."
