YOU SAID:

cookie went to a cookie shop to buy cookies, but they were out of cookies so she ate them.

INTO JAPANESE

クッキーはクッキー屋にクッキーを買いに行きましたが、クッキーがなくなっていたので食べてしまいました。

BACK INTO ENGLISH

I went to the cookie shop to buy some cookies, but they were gone, so I ate them.

INTO JAPANESE

クッキー屋さんにクッキーを買いに行きましたが、なくなっていたので食べました。

BACK INTO ENGLISH

I went to the cookie shop to buy some cookies, but they were gone, so I ate them.