1) it could mean your gullible because your obviously being lead into a trap and need to learn a lesson so it doesn't happen in real life 2) it's just a dream 3) You need help from other people to save her 4) you feel guilty because you couldn't save someone in real life in a similar situation
Honestly, this could mean anything. People have dreams that don't ever have anything to do with their daily life. Sometime it's just a recollection of events that have happened ( I don't think anything has happened to you like this..?) dreams most of the time are just our brain of either remembering your day and reflecting maybe something that has been on your mind. Are you stressed about something specifically? It could just be your mind re thinking something that is even moderately stressful. Anyways, I don't think this dream has much to do with you not being able to not save someone or make the decision, sounds like a pretty general dream.
It could mean that there is some sort of obstacle that you are trying to get over in your life. Saving the girl in your dream was the goal. When she told you not to help her, she could have been your subconscious thwarting you in your goal. Her saying no could really have been an example of fear of failure. If you were the girl, a fear of success. By avoiding your goal, then going back to it, you may have created even more obstacles, such as the enemy telling you to leave.