Does donating money in exchange for free games previously obtained from an employee without his manager's permission remove the sin and the fear of unlawfulness?

The questioner is suffering from waswasah (whispers/obsessive thoughts), and she must turn away from them. If the worker is authorized to dispose of the toys, then there is no harm in gifting them. The shar’i (Islamic legal) ruling for someone who takes something belonging to another without right is that they must seek forgiveness and pardon from the owner of the right, or guarantee what they took to him. Giving charity on behalf of the rightful owners does not suffice unless one is unable to reach them; with the ability to do so, the right must be delivered to them or their forgiveness obtained.