Sec 419, 420, 120B, 468, 471 second time

Dear members, my sister works in my office as a trainee and without knowing the consequences, she signed 2 invoices on my name (I was out of Delhi, I did not ask her to sign on my behalf) and sent the invoices to client, who recognized that signature were not mine and filed a police complaint, police filed FIR U/S 419, 420, 468, 471, 120B. nWe talked to the client but being an international company they declined to compound saying they take these things very seriously. We went for plea bargain and my sister was left with a warning and 6 months probation, now the other client has filed the same complaint against us under the same sections. My sister is 25 years old and she had no idea, it will become such a big deal, she is a student, doing CA. Is there any way we can save her from going to jail, as this is the second FIR under same sections, compounding and plea bargain is not available. Both of the invoices were signed before her first conviction. What should we do? please help.