SOLVED. a vintage store owner tracing memories of a departments store through her diary [s]

[Yang]

One of the two women’s name is Oliver;
And the diary’s owner was once rich before their family went bankrupt and her father died;
The vintage owner, a lady, had an affair with a married man;
Chapters are arranged separately like in parallel spaces, with one chapter in the point of view of Oliver, and the next in the point of view of the other woman.

Thank you very much!

[Stephanie]

If you meant one of the women was named Olive, this sounds like Astor Place Vintage.

[Yang]

Thank you very much! That is exactly the book I read :)