Ex best friend who knows to much :( help?

[Catch. Me ♥]

so i just recently "broke up" with my friend . we are no longer friends anymore because i didn't like her personality and who she has become. I was tired of slowly not becoming friends with her and last night i was really upset with her because she was being all innocent with her texts but there were secret messages behind each and everyone of the texts. and they were bitchy. She told me to stop texting her and so i did and i just texted her one last thing ; that i didn't want to speak to her or have any contact with her. That this friendship is over. Knowing her, she might spill all my secrets or spread nasty rumors. she deleted me off her facebook and twitter and it wont let me send her a inbox to tell her not to. My friend told me not to tell her that because then she wud definitely do that. My other guy friend, decided he will talk to her and see if she would say any shit about me.

What should i do? Do you think she would spread things about me? she goes to a different school but knows some people from My schoool [because of me].
Please help