Is my little cousin okay?? shes so different now?

she used to be so happy and laughing and dancing around the house and just a normal little girl and plays with her dolls and makes up little princess stories. now she is so quite, doesnt move an inch and never really talks anymore. shes like a totally different little girl...shes doing bad in school and does not pay attention during cl like she used to and at recess she just sits against the school building and doesnt play. she is a goregous little girl and "was" very outgoing. she does allstar cheer and dance and she loves practice, when she is at practice that is when she zones out and tumbles her little away and she just seems relieved to be there and she never wants to leave but once she has to leave shes right back to being the sad little girl no one knows anymore. i ask her if something is bothering her and the look she gives me just breaks my heart, its like she wants to tell me something so bad but she just cant let it out her mouth. and i will say baby whats wrong and she will cry and just hold on to me and still never say a word then i will rock her to sleep and she will sleep for hours as if she doesnt sleep when shes at home.i asked her parents..well i said her mom and her new step dad have they seen anything differnt in her like i am seeing and her mom just dont say much all she will say is " oh shes fine dont worry about her" then she walks away but the step dad glares at me and dont say anything and just goes into the room and dont come out until i leave. so i asked her is she scared to be home for any reason and she didnt say anything,she just looked at me once again with that sad face. I told her to draw me a picture and she did, she drew her house and she blacked out her bedroom window, like she colored only her window completely black and no other ones and i asked her why was her window colored back and she just shrugged her sholders and put her head done and didnt want to color anymore. i dont know what to do.. she is my baby girl and i hate seeing her like this...its been about 2 mouths with this new behavior. what in the world do you think is going on with her? she is 7