No offense, but if I was with someone who had a history of lying to me or acting in ways that were detrimental to our relationship, I would be pretty snoopy at the signs of lying, too. Regardless of whether or not I said I would avoid a certain site or blog.
In my mind, I know two wrongs don't make a right, but to me it makes the second wrong a hell of a lot more understandable. Assuming it isn't physically hurting someone or something like that.
You broke her trust, why shouldn't she break yours? Comes back to the good ol' Golden Rule - Treat others the way you want to be treated. Until you prove to genebean you can be trusted (by telling the truth - especially when asked straight out), why should she show any trust in you?
I'm not saying she was justified in coming here to find out what you've been saying, but it really seems like she had no idea what's going on with you and this was her best bet at finding out since you weren't talking.
Now, on a less judgmental/harsh note... I understand not wanting to tell details when you haven't had time to process, but there is no reason you couldn't tell her that yes, you were interested in someone and thought there COULD be interest but until you've had time to really think it over and examine what is going on you didn't feel comfortable sharing. Then set a time in the somewhat near future to talk about after you've processed a bit. Lying shouldn't be an option, but saying you're not ready to talk about it yet can be.