What should I do in this situation?

I have a situation with a girl. I've known her for a year or so. Two weeks ago she contacted me and was telling me how she was in to me. I had no idea. She had a boyfriend for as long as I knew her. I didn't even know she was single. We talked for the first night around 4 hrs. The next day we talked for a few hours as well. On day 3, I got a text saying I miss you and want to see you. I took her to dinner. She was all over facebook talking about an amazing night. The next couple of days we saw each other and talked at night. We were supposed to go out Friday night, but she text me a few hours before and canceled due to dinner plans with her family. I didn't get mad, but I was a little upset due to getting my car clean, getting flowers, and making reservations. We had made plans to do that then go watch a game with some friends. She did come to game. I was a little standoffish at first, but she came right to me. She snuggled with me on the couch that night and asked me to contact her the next day. I did and never heard from her. The next day we were at church and she came and sit with me and said that she would contact me that day. I never heard from her. I didn't hear from her the next two days. Finally, 3 days later, she came to church and talked to me. She apologized for canceling and said she chose to go with parents due to neglecting them so much during her last relationship. She said she was sorry for not talking to me, but she was dealing with her ex. Her and her ex got into the day before and it got so bad she slapped him. I talked to her the next day and she said on her way to cl she was afraid to drive, so she called him and had him follow her to cl. She also told me how she was talking to a guy who was older that she met at her job. She met this guy while dating her ex. She and her ex dated for 3 years. She had been talking to the older guy for the last 6 months. I also know of a friend she contacted while dating her ex. She was trying to get my friend to go out. She says the older guy turned out to be 30, recently divorced, and has a kid, so she was done with him. At the same time, she was telling me what an amazing guy that I am. The next day after we talked all night she puts on facebook she is thankful for the man she has in her life and how she is so happy. I see a few red flags. The major red flag is how she talked to guys while in a relationship with her ex. Three years is a long amount of time and one should not be cheating at that point. I also caught her in some lies throughout our conversations. Here is the situation: I like her, but she is only 18 and I am 23. I can see a lot of immaturity in her. I also do not trust her. I can't trust someone who lies from the start. I realize I can't expect her to just go out with me due to us not being in a relationship, but she and I made it clear that we were talking and were thinking something exclusive. I feel that if you want to be inclusive, cool, but at least tell someone. Don't go around snuggling and calling someone amazing, then go out with other guys the next couple of days and not talk to the person you snuggled with. I like her cause she is sweet and fun to be with, but I don't think she is ready for a relationship due to only being broken up with ex for less than 2 months. I also feel that she may have just rushed into getting to know me and needed a rebound. She has made the point to me that she can't stand to be alone and doesn't really know how too. Right now I am just taking a step back. There are no feelings involved other than me liking her. I am giving her space and just letting her be her. I'm I doing the right thing? I am debating on whether I should contact her and there and be friends until she decides on what she wants or just dropping her and moving on. What is your advice?