Can you help me with another awkward situation?

This friend of mine had my cellphone to make a call and then I noticed her going through my texts. She thought I couldn’t see her doing it. I ignored it and now it’s annoying me. Especially because she keeps subtly using some of the info she gathered from my texts and taunting me with it. However it’s not so obvious that I can accuse her straight up of having read my texts. Because if I hadn’t known she’d read my texts I would assume it’s stuff she found out elsewhere or knew before hand.

Now I have two questions:
1. How would you have confronted a friend about this right when you noticed her going through your texts?
2. What would you do now that she’s acting annoying with it?

I’d very much appreciate that you don’t say that I should put up with it now that I didn’t confront her earlier etc.

Go, collective.