Lack of empathy in child has me concerned?

My teen is becoming all about herself. We take long walks in the park lately. Today, I had to sit in the car with broken air conditioning and it is 90 degrees here. She wanted to jog. I wasn't feeling well after she was late getting out of school.We were jogging and I stopped. I told her I didn't feel well because of the hot car. She one-upped me and said "Well, I have to sit in school all day where it's too COLD, so you should be happy!".This happens all day, in all situations. She asks what I did today, then says she worked harder/had to do more/whatever. I explain to her that we are not having a competition. This usually shuts her down.However, I broke my leg/ankle in 4 spots last year. She would come home from school and tell me her day was so much worse than mine (physical therapy, peeing in a pan, horrible pain from surgery) and I am really concerned for her lack of empathy. That is when this started. I am just now back to jogging, and she makes fun of how much faster she is than me. She just did this today. I try to tell her she's very hurtful, but she almost likes the bullying. She gets a power kick and smiles when I explain she can be very mean.Selfishness: Everything in the house is "hers". She will come home from her dads and open the fridge and whine "Why did you drink all the milk while I was gone?" Meanwhile, there is a stretch where she can be gone for 5 days and she knows this.No communication: If I ask her to please do anything (please shower soon for example) she will not say a word. Then, I have to repeat, "did you hear me?" Which always results in a "YES OH MY GOD MOM I HEARD YOU JEEZ!" Why can't she just say "ok."? This goes for all requests. If she doesn't want to do it, she cops out by saying "I didn't hear you".On the drive home today, she mentioned how the neighbors feed a cute squirrel that used to come to our home. Now, he takes all the food from next door. She told me she is walking right over there and "taking all their peanuts right from their porch". I don't know where this is coming from. She knows better than to steal. I told her that is stealing and she said "Who cares, I will just put him in his place (the neighbor).". I do not talk like this so I don't get it.She also admitted she "Does not care what anyone thinks" and also "Does not care how she looks" last week. I don't chase her around with a brush anymore.I really think she wants to hurt people on purpose, especially me. Her father is never around (separated-always on long business trips) and I do the hard parenting here. Thanks for reading. I would like to see some opinions. via /r/Parenting http://ift.tt/2xeYyjF