Helpp Pleaseee with girll drama?

Okay so basically these group of girls i hate hacked my acounnt on msn but i hacked one of them back lol..... and she got mad so she msg me telling me she was gunna come to my house with her older sisters to have "a talk with me" me and these girls have had alloot of fights... so i have a felling she is gunna bring her sisters too cuss me off or sumtin...... i am not scared or nuttin its just i find it really anyyoing how shes always starting shiett with me so if she does happen to come to my house can i call the police on her for tressping or sumttinn.....? like do i just call 911 or???>> Hellpp