That's because she bought something there it's just she can't recall which store it was.
It is exactly something I would do.
Like coffee shops for me, there are so many. Ones i've wandered into, for the life of me I wouldn't remember the name, weeks later, let alone months. I might not have even noticed the name at all while I was there.
I wouldn't have a chance in hell at remembering it if it was in Chinese.
I would say that a lof of coffee shops are similar as are Asian grocery stores.
It doesn't mean she knows the area well and even if she did, it's not strange or dishonest or against the law to forget where you bought something months later.
Maybe hypnosis could be used to narrow it down.