Is a female employee sinful for taking a portion of the money given to her to distribute to the poor among employees, when the manager did not specify her share?

The agent is obligated to adhere to what they have been entrusted with and not to contravene it, as they are in a position of trust. If the principal grants the agent full discretion, the agent must act according to what is customary; otherwise, they should act according to what they most likely believe to be the principal's intention. Accordingly, if there is a custom for the amount of the reward, it must be adhered to. Otherwise, there is no sin upon you for what you have taken, as long as you have not done anything that contradicts your manager's intention.