I texted this:

"I don't mean to leave you in the dark. I was just taken back by everything the last couple of weeks, and I needed to process it in a healthy manner until I could talk about it with you. I'm having a rough time accepting that you told (so and so) something that is so personal and sensitive to me. Something that I'm still trying to accept and something that my family didn't even know at the time. I'm not mad, it just hurt me. I know you didn't mean to upset me, and I will get over it. I just need some time. I hope you understand."

How's that? I haven't received a response yet, but I already feel so much better just letting it out regardless of what her response is.