Honestly, the Russians are just trying to get leverage out of this.
The woman broke their laws, and should go to jail. They know it, I know it, the US government knows it, even her lawyer knows it. However, if they could get something for it in trade, it seems like a good deal for them.
Who really wants to pay money to provide her prison time, food, and security (Because if anything happens to her in jail it will be an international affair)? Not Russia if they are smart.
More likely than not, the US will make some concession to get her out that will hurt our nation but make the Biden administration out to be ‘good guys’.
Yes they are using this as leverage.