I think the one that Momtoatrio is talking about is this one.
Mini Mysteries

I've seen the books in this series at Books a Million; I think there's several different ones. They are not about the historical girls. Some of these stories have been printed in the AG magazine a lot too.

I would like to hear a review of the new book also. Here's a link for anyone who wasn't aware of this title.

Historical Minute Mysteries