Itachi could respect dedication. Everyone needed to put in extra hours of work if they wanted to be more than average, and Ami certainly seemed to have the drive to do that. The question was did she have the sense to not push herself too far.

"You should be sure to stop before you have blisters." After he spoke Itachi had the thought that he should have alerted her to his presence before speaking.

If he got stabbed by Shisui's gennin, no one would ever let him live it down.