eh.. it's obvious she has 2 animations that really differ. it's for both of her hacking games. one she lifts her arm all the way up, the other she hits the direct object. she always does the all up one first time for first hack. but she can do 1 more and I'm sure then it's slower. but I managed to shoot her once she did that for her 3rd move and still get a good opening. for the 2nd hack, I doubt it saves any time to shoot her, unless she does all up move, then you better shoot her, so you won't lose time then I don't think. then just make sure she gets to her lovely table in the desired time, because she can be held up by a guard or not doing her warp or whatever.
if that 4/6/8 sec is correct, than I assume 6 sec is 1 all up move, 8 sec is 2, and that move loses 2 sec.
I think it should be looked into if the protection is slower if she does any all up moves during her hack. shoot her whenever she does, try to not let it happen and such.