So maybe I was more than "somewhat" defensive

So as I'm finishing up my blog post from last night, and settling into the stats and counters and whatnot, my kid comes up behind me. She spends so much time at my desk and on my computer that she seems to think that everything that goes on at the desk and on the computer is up for her approval/critique/perusal. Of course, nine times out of 10, I'm doing bills or something boring. Last night, I was on a site she hadn't seen and doing something on a page she didn't know.
"Wait. You blog?" she asked, somewhat incredulously.
"Yes; yes, I do," I said, somewhat defensively.
"Huh," she replied. And then she walked away.
I'm not sure why it bothered me that she was all surprised that I'd be blogging, or is she more surprised that she didn't know I blogged at all. Either way, it was a weird exchange, in that she didn't have any follow-up questions.
Honestly, I'm not even sure I'd be ready for her dive into this thing. I don't fear answering any questions or justifying any of my opinions, but it would be really a lot for her to process, I would think. Like finding all my mom's diaries, if she had any, or my dad's confessional selfie videos or something. Just a lot to process. Over like 15 years or whatever.