Answer:
According to Gies, the motivation was simply the fact that she wanted to help and she would have felt regret, if she let innocent people die.
Step-by-step explanation:
Till the end of her life, Gies, never considered herself a hero. She explained that it was human nature to help someone and clearly stated, that by calling her actions 'brave' or 'heroic' would put on her on a pedestal, and demotivate other people to act out kindly when needed.
Gies was Dutch and had worked with Jewish people before. She felt empathy and always thought her actions were natural, human and not at all special.