My 'best' friend now wont talk at all?

Tbh no offence or anything but if someone tried looking at what i was doing whilst i was doing something on my phone i would be annoyed, It seems like she didn't want to tell you what she was doing, and that is her choice, best friends don't need to know everything about each other. This all seems a bit girly and pathetic, be mature about things, if you really want to be her friend you wont mind apologizing.