The sentence is もー、かがみがこんなにエロかったなんて初めて知ったよ. 再確認 is part of a sidenote of sorts; you can tell by the smaller text size. It looks like あえイミ再確認, or maybe あ…イミ再確認, but I'm not sure.
I thought that 知ったよ and 再確認 were both sidenotes, and the vertical placement made me think they were one sentence. The placement of あえイミ threw me off though.
Based on your translation then, is 初めて知る something like "to learn for the first time"?
I can't make a る out of that no matter how hard I try, but you're probably right.
Good morning Kagamin.Wh-Kagami-sama?Konata......I don't like doing this sort of thing so early in the morning.........sorryJeez Kagami, I had no idea you were so naughty!
though it's more like a reconfirmationIt's just that I was still half asleep
...Where should we go today?Heh..Akiba!