Wait wait wait.... WTF?
In chapter 6 she clearly tells them that the magic stone is in a freaking mountain! Now it's suddenly in a city slum?
She sold the information on the stone, and they clearly stated that they would retrieve it, so what is she doing here?
Is she suddenly aware of multiple (super rare/super valuable) magic stones and never bothered to point out that little detail?
Please remember, she is supposed to be country farm girl who re-incarnated into a book world she once read. Why would walking around slum streets possibly jog her memory of the stones location, if she's never been there before? Do you seriously expect the readers to believe that this super valuable thing is within reach of someone wandering the slum streets?!