Will the questioner be punished if she refrains from teaching her colleague, to protect herself from her treachery and the treachery of her manager who supports her? What is the solution from your point of view? And does her inability to forgive her former manager for his injustice deprive her of the reward for forgiveness mentioned in the noble Hadith: "Whoever forgives his brother, Allah will forgive him on the Day of Resurrection"?

The relationship between the questioner and the company is one of ijarah (definition) (hiring/leasing), and her task is to perform the work for which she was hired, not to teach others. The hadith (definition) "Whoever is asked about knowledge and conceals it" does not apply to her.

If the former manager dismissed her during the contract period, he was unjust, because a contract of ijarah is binding and cannot be terminated except with the consent of both parties or for a legitimate Shariah-compliant excuse. In this case, it is recommended to forgive him. However, if the dismissal occurred after the contract period ended, there is no injustice.