As someone who once served on the police applicant review board, here are my thoughts. I am telling you these things so you can better prepare yourself to address them if someone else should mention them to you during the application process.
You are a very ambitious person, and are well prepared academically and physically. I don't understand why you are doing both police and fire, and am concerned you might decide at some point to leave the police department and go to the fire department. This means all the time and money we have spent in training you will have been wasted. Or, you might not understand at a fire scene that you are not a firefighter - if you are there as a police officer, we need you to do your job as an officer - not a firefighter.
However, my biggest concern is that you are not psychologically prepared. Young people, especially women, approach law enforcement with an idealistic view about "making a difference in the world." You still live at home, which makes me think you have limited exposure to certain life experiences. When you become an officer, and see the magnitude of the problems in society, you may begin to feel that it is overwhelming. You may also become disillusioned because you don't have time to spend just talking with people and trying to help them - instead, you simply give them a phone number to social services, and move on to the next call. Many women who get into law enforcement do not make it a career. We want to make sure you are one who is going to stay.
How to prepare psychologically? I would start doing some volunteer work in places such as soup kitchens, homeless shelters, halfway houses, etc. Get yourself out there into these parts of society that you may have been sheltered from. Don't work in the back office - get out there and mingle with the people.
I hope this has been helpful. I enjoyed my time as an officer, and hope you will too!