Keeping Him Alive

Just another zombie story I must say, but I would love it if you will take some time to read and give me some feedback.
The story is of a girl living in a world full of the dead. She and her little brother must survive this living hell. Ana tries to keep Danny safe because he is the only reason why she breathes and moves. She teaches, and sets an example to Danny. Ana's six simple rules are...
1) No crying
2) Stay strong
3) Remember you are the future of humanity
4) Kill if you have to
5) Stop sucking your thumb.
6) Live