"When a smart and lonely charlatan is mockingly deceived by a criminal financier, she puts together a gang of female con-artists, to get the businessman’s financial empire to collapse."

Needs a grammar and word choice check. It’s “gang of female con-artists”, not “gang of female con-artist, and “the businessman’s financial empire to collapse”, not ” the businessman financial empire to collapse”.

First impression is that the protagonist being a charlatan doesn’t make for a sympathetic character. The deception could be well-deserved comeuppance even if it was the act of a criminal.

Somewhat clearer, but shouldn’t her objective goal be to get her money back for her daughter’s eye operation? She may want to take down the criminal as revenge — but that’s a bonus. Her primary goal is to get the money she needs for the surgery.

And “she must learn to become a con artist” is weak. Something like “she masters the art of the con” or “becomes a con artist” is stronger. The suspense in the story, the moment of truth, is not in the learning but the doing — can she pull off the con? (Of course, she must learn but that builds up to the moment of truth.)