Whats this girls deal?

So im 16 and recently transferred to a diffrent school where I met this girl who had just moved in from another state, and so I would talk to her every now and then in school, and even let her borrow my ipod because she lives in my neighborhood, therefore i could go pick it up anytime. Even though she has a 3 year old kid and is going to turn 18 because shes 17 I considered dating her. So during the summer I go to her house to get my ipod back, she greets me at the door nicely and tells me she cant find it because her room is messy and her sons toys are all over the place, so I tell her too please go look because i neededit that night. Anyway we ended up having a long conversation about her friends and what not until I finally tell her sister that if she finds my ipod i would give her 10 dollars. Eventually she comes out with my ipod and I go home. While we where talking though, she said to me that I dont look sexually active and that It looked like I had never kissed a girl or had a girlfriend, which shocked me and I told her that it pissed me off when people said that. Maybe its because I didnt really hit on her as much as just ask her alot of questions in the effort to get to know her better.

Well a few days went by and I went back to her house so that she could save all the pictures that she had taken on her computer which she asked me to do. As I got there she's sitting on the stairs with her sister and starts asking me what im doing at her house and that she thought she had told me to not come to her house again. I was shocked and thought that she was acting like that because her dad had caught her talking to me a couple days before and she didnt want to get in trouble.

So I didnt pay much attention to that and a few weeks later go back to her house to ask her if she wanted to drink, and this time she opens the door and tells me the same thing and jest shuts the door closed in my face. Well i figured she didnt want anything to do with me, I thought that maybe I was too young for her and she was looking for someone older considering she had a kid and the kids dad was in his 20s and having a kid with another girl, but later I find out that she dated this 10th grader for a few days who is now claiming that he "f*cked her", and even some of his friends are saying they where there when it happened. She doesnt talk to him anymore but they did go out for like a couple days and supposedly he banged her too.

So im here thinking she completely rejected me a pretty mature 16 year old and went out with a gangster wannabe though acting 15 year old who claims to have had sex with her. What is up with this girl?

Also a few days ago I was riding my bike with some younger kids that know me because I volunteer at this after school program every now and then, and she was with her son talking to one of her sisters younger friends and I said hi to her sisters friend. Later that girl who I said hi to tells me that after I said hi to her she asked her if she knew me and this girl says no. She denied knowing me.

I think theres something wrong wit this girl but could it be she dislikes me that much and is embarrassed to let people even know that she does know me?

Im just confused what do you guys think.

FYI the girl was 10years old to whom she denied knowing me to.