Is it the case that one who was brought up on the money from usurious banks insists on committing sins such as lying and slandering others, and is this due to ill-gotten gains?

If your colleague consumed unlawful wealth when she was young or under duress, there is no sin upon her. Otherwise, she must repent from consuming unlawful wealth and return what is due. It is advisable to remind her of the danger of unlawful wealth and to continue advising her with wisdom and good counsel regarding the blameworthy character traits she possesses, such as lying and slandering people, and not to hasten the expectation of a response.